These outputs are very important to diagnose your issue.
hwinfo --netcard --wlan --bluetooth | grep -Ei "model\:|driver\:|status\:|cmd\:|file\:|detected\:" | grep -v "Config Status"
lsmod | grep r816
dmesg | grep -iE 'enp|eth|firm'
lspci -knnvvv | grep -i net
Have you tested other kernels yet, (if not you should). I would suggest installing and testing both older and newer kernels. Try at least two or three alternate kernels. Install kernels through Manjaro Settings Manager, and always have at least two kernels installed at all times for safety.
- The first step in troubleshooting any LAN issue should always be rebooting the router and computer.
- Test different cable ports on the router.
- Have you tried different network cables, (min cat5e, preferably cat6e).
- Ensure the NIC speed is set to auto-negotiation in Network Manager.
- Try removing the LAN card (if not onboard) and swap it to another slot (if available).
- Try assigning your computer a static IP address via MAC address association through your router configuration settings.
Also try this:
Power down the laptop and remove the battery and power plug. Let the laptop sit without power for a few minutes. Then, hold down the power button for approximately 30 seconds. Pressing the power button will help drain all left over power from the unit’s motherboard.
Then reattach the AC power (no battery), and restart. Boot into your bios, then reset the bios to the factory defaults, save the default settings. See if it will boot correctly with the factory default settings. If not, you may have to change a few settings in the BIOS (such as secure boot) to get Manjaro to boot correctly. After rebooting your adapter may be properly detected and initialized.