Please, consistently:
- Shut Windows down completely
- Wait for 1 second
- Turn the machine back on
- Boot Manjaro
Because there probably is a bug in the Windows driver or UEFI firmware. This is called a Cold boot. I.E. Do not reboot from Windows and then start Manjaro (Warm boot)
That’s good, so that’s not the problem.
Try the following:
- disable power saving by adding
power_save=0
to/etc/modprobe.d/iwlwifi.conf
- If the above doesn’t help, try the 5.4 LTS kernel (Intel had some issues in the 5.7 kernel, maybe they’re not all gone), keep the parameter above there as well
- Please provide the full contents of
/etc/modprobe.d/iwlwifi.conf