eth network no connection after rebooting from Windows 10 to Linux

I’m dual-booting Windows 10 and EndeavourOS.  Somehow, Windows messes with my network card so that, when booting Linux, I can’t reach the network.  When I first encountered this, I reinstalled EndeavourOS and it was working fine again.  But only until the next Windows boot and successive Linux boot again. Also, the NIC is working fine when starting from an EndeavourOS live USB stick. That’s the NIC:

[me@pc ~]$ /usr/bin/lspci | /bin/egrep -i 'network|ethernet'
01:00.1 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 1a)

I found lots of rather old threads suggesting turning off all sorts of wake on LAN and other power settings in Win 10, tried them all but to no avail. Interestingly the NIC does seem to get a correct IP address via DHCP. Upon login to KDE, the NIC has its last DHCP config remembered, it seems:

[me@pc ~]$ ip a
1: lo:  mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp1s0f1:  mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether e0:4f:43:e8:12:e3 brd ff:ff:ff:ff:ff:ff
    inet 192.168.99.10/24 brd 192.168.99.255 scope global dynamic noprefixroute enp1s0f1
       valid_lft 43007sec preferred_lft 43007sec
    inet6 fe80::48e3:71dd:df1b:797b/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: wlan0:  mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 9a:11:4e:51:2b:86 brd ff:ff:ff:ff:ff:ff permaddr 9c:fc:e8:dd:b1:2f

However, no connection to the network:

[me@pc ~]$ ping 192.168.99.10
PING 192.168.99.10 (192.168.99.10) 56(84) bytes of data.
64 bytes from 192.168.99.10: icmp_seq=1 ttl=64 time=0.031 ms
64 bytes from 192.168.99.10: icmp_seq=2 ttl=64 time=0.058 ms
64 bytes from 192.168.99.10: icmp_seq=3 ttl=64 time=0.057 ms
^C
--- 192.168.99.10 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2053ms
rtt min/avg/max/mdev = 0.031/0.048/0.058/0.012 ms

[me@pc ~]$ ping 192.168.99.1
PING 192.168.99.1 (192.168.99.1) 56(84) bytes of data.
From 192.168.99.10 icmp_seq=1 Destination Host Unreachable
From 192.168.99.10 icmp_seq=2 Destination Host Unreachable
From 192.168.99.10 icmp_seq=3 Destination Host Unreachable
^C
--- 192.168.99.1 ping statistics ---
6 packets transmitted, 0 received, +3 errors, 100% packet loss, time 5226ms
pipe 3

[me@pc ~]$ sudo dmesg | grep r8168
[    6.133867] r8168: loading out-of-tree module taints kernel.
[    6.242244] r8168: module verification failed: signature and/or required key missing - tainting kernel
[    6.244316] r8168 Gigabit Ethernet driver 8.048.03-NAPI loaded
[    6.262759] r8168: This product is covered by one or more of the following patents: US6,570,884, US6,115,776, and US6,327,625.
[    6.264779] r8168  Copyright (C) 2020  Realtek NIC software team  
[    6.512649] r8168 0000:01:00.1 enp1s0f1: renamed from eth0
[   10.578772] r8168: enp1s0f1: link up

I also tried switching to a slightly older version of r8168 module (lts), to no avail. I remember it to work, switching back and forth between Windows and Linux, but at this time only reinstalling seems to help. Which I want to, of course, circumvent. Even if it means resetting the NIC somehow during startup or other hacks. EDIT New evidence: I configured the NIC manually via NetworkManager, and now it is constantly disconnecting and connecting again:

Apr 13 10:40:27 pc NetworkManager:   [1618303227.2299] manager: NetworkManager state is now CONNECTING
Apr 13 10:40:27 pc NetworkManager:   [1618303227.2513] device (enp1s0f1): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
Apr 13 10:40:27 pc NetworkManager:   [1618303227.2520] device (enp1s0f1): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
Apr 13 10:40:27 pc NetworkManager:   [1618303227.2546] device (enp1s0f1): state change: ip-config -> ip-check (reason 'none', sys-iface-state: 'managed')
Apr 13 10:40:27 pc NetworkManager:   [1618303227.2587] device (enp1s0f1): state change: ip-check -> secondaries (reason 'none', sys-iface-state: 'managed')
Apr 13 10:40:27 pc NetworkManager:   [1618303227.2589] device (enp1s0f1): state change: secondaries -> activated (reason 'none', sys-iface-state: 'managed')
Apr 13 10:40:27 pc NetworkManager:   [1618303227.2596] manager: NetworkManager state is now CONNECTED_LOCAL
Apr 13 10:40:27 pc NetworkManager:   [1618303227.2605] manager: NetworkManager state is now CONNECTED_SITE
Apr 13 10:40:27 pc NetworkManager:   [1618303227.2607] policy: set 'Wired connection 1' (enp1s0f1) as default for IPv4 routing and DNS
Apr 13 10:40:27 pc NetworkManager:   [1618303227.2640] device (enp1s0f1): Activation: successful, device activated.
Apr 13 10:40:35 pc NetworkManager:   [1618303235.3135] device (enp1s0f1): carrier: link connected
Apr 13 10:40:35 pc NetworkManager:   [1618303235.3142] device (enp1s0f1): state change: activated -> unavailable (reason 'carrier-changed', sys-iface-state: 'managed')
Apr 13 10:40:35 pc NetworkManager:   [1618303235.3667] manager: NetworkManager state is now CONNECTED_LOCAL
Apr 13 10:40:35 pc NetworkManager:   [1618303235.3678] manager: NetworkManager state is now DISCONNECTED
Apr 13 10:40:40 pc NetworkManager:   [1618303240.3191] device (enp1s0f1): state change: unavailable -> disconnected (reason 'none', sys-iface-state: 'managed')
Apr 13 10:40:40 pc NetworkManager:   [1618303240.3223] policy: auto-activating connection 'Wired connection 1' (e76e5718-9a47-3733-818b-30aaa862bcf4)
Apr 13 10:40:40 pc NetworkManager:   [1618303240.3235] device (enp1s0f1): Activation: starting connection 'Wired connection 1' (e76e5718-9a47-3733-818b-30aaa862bcf4)
Apr 13 10:40:40 pc NetworkManager:   [1618303240.3238] device (enp1s0f1): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
Apr 13 10:40:40 pc NetworkManager:   [1618303240.3247] manager: NetworkManager state is now CONNECTING
...start all over

So the NIC itself is working now, but only to a degree:

[me@pc ~]$ ping 192.168.99.1
PING 192.168.99.1 (192.168.99.1) 56(84) bytes of data.
ping: sendmsg: Network is unreachable
ping: sendmsg: Network is unreachable
ping: sendmsg: Network is unreachable
ping: sendmsg: Network is unreachable
From 192.168.99.8 icmp_seq=12 Destination Host Unreachable
From 192.168.99.8 icmp_seq=13 Destination Host Unreachable
From 192.168.99.8 icmp_seq=14 Destination Host Unreachable
64 bytes from 192.168.99.1: icmp_seq=15 ttl=64 time=1.65 ms
ping: sendmsg: Network is unreachable
ping: sendmsg: Network is unreachable
ping: sendmsg: Network is unreachable