Sorry, I'm going from memory what Google says are 'issues' with Wix Forum pages on mobile.
I think what I put is correct? It's certainly something like that. It always says the same 2 things. It doesn't like that the page isn't set to device width/size, and the fact you can't zoom it says as well.
Obviously these things damage the forums search engine rankings, otherwise Google wouldn't be bringing it to our attention. They make very clear that anything which makes your mobile site version unfriendly, will have a negative impact on your ranking.