Well the problem will be solved if you like LXQT and want to install it. Lxqt is rather minimalist and is more suitable for older hardware. As your hardware is not that old that may not be a desktop that intests you.
If it works on Lxqt it tells us through a process of elimination which networking components are more likely to be causing your issue. It is more of a troubleshooting step than a solution. However, I guess if you like Lxqt and don't mind installing and using that desktop then your problem would be solved as far as your networking issue goes. 