I had a problem with a Dell latitude when booting the laptop with usb-c adapter (hdmi/eth/usb-a/charge pass through): both eth and wifi didn’t work.
When booting without adapter everything was ok.
I solved this way:
In /etc/modprobe.d/blacklist.conf I added these:
blacklist cdc_ncm
blacklist cdc_mbim
blacklist cdc_ether
blacklist usbnet
In /etc/modprobe.d/iwlwifi.conf I added this:
options iwlwifi power_save=0