VMG3925-B10C vs Google Nest Mini

I have a VMG3925-B10C router and have recently got a Google Nest Mini - I have seen a few threads about this but despite trying to work through some of the fixes I am really struggling - the Nest works fine on a hotspot and been told by Google/my internet provider it’s the router - can anybody help me? I am not the most technical so will need it in very basic instructions! Thanks