No internet connection (both ethernet & wifi) after 24.04 upgrade

I have just updated to Ubuntu 24.04 LTS on my laptop, and I seem to be having internet issues. While both Ethernet and Wi-Fi were working in the previous version, I now have no internet connection through either. When the PC starts, it shows as connected via Ethernet or Wi-Fi, but there is no internet access. The internet only works after I run this command: dhcpcd