suddenly wifi internet disconnection

I have sometimes internet disconnection from my wifi connection to my home wifi modem. I have one Linux LMDE OS into my Lenovo IdeaPad 310 laptop, so in regular times I have this: so@notebook:~$ uname -a Linux notebook 4.9.0-9-amd64 #1 SMP Debian 4.9.168-1 (2019-04-12) x86_64 GNU/Linux   so@notebook:~$ ifconfig            wlp2s0: flags=4163  mtu 1500        inet 192.168.1.105  netmask 255.255.255.0  broadcast 192.168.1.255        inet6 fe80::59dc:548c:4eb2:a3e5  prefixlen 64  scopeid 0x20        ether c8:3d:d4:3c:23:63  txqueuelen 1000  (Ethernet)        RX packets 50050  bytes 46065327 (43.9 MiB)        RX errors 0  dropped 0  overruns 0  frame 0        TX packets 40256  bytes 6564953 (6.2 MiB)        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0 but when my wifi internet disconnected I have this: so@notebook:~$ ifconfig            wlp2s0: flags=4163  mtu 1500        inet6 fe80::59dc:548c:4eb2:a3e5  prefixlen 64  scopeid 0x20        ether c8:3d:d4:3c:23:63  txqueuelen 1000  (Ethernet)        RX packets 50203  bytes 46102351 (43.9 MiB)        RX errors 0  dropped 0  overruns 0  frame 0        TX packets 40387  bytes 6581340 (6.2 MiB)        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0 and my wifi setting could be seen here: **Update:** Based on comments I have: so@notebook:~$ lspci -knn | grep Net -A3 02:00.0 Network controller : Realtek Semiconductor Co., Ltd. RTL8821AE 802.11ac PCIe Wireless Network Adapter [10ec:8821] Subsystem: Lenovo RTL8821AE 802.11ac PCIe Wireless Network Adapter [17aa:a814] Kernel driver in use: rtl8821ae Kernel modules: rtl8821ae 03:00.0 3D controller : NVIDIA Corporation GM108M [GeForce 920MX] [10de:134f] (rev a2) So why this happened?