Ethernet Internet Access workiing intermittantly - Why?

[pymason]

Hi. My daughter's Nexus 7 running Android 6.1 (I think), is intermittantly working and then not working on it's ethernet internet connection. This started after a system update and seemed to correct itself a few days later, but then re-occurred, and now appears to have stuck not working.
Anyone out there had anything similar happen? Is it a setting that gets reset on update?
I would be grateful for any help on this - I've exhausted my ideas on this one...
Many thanks...