Users can post to forum on PC, but not with mobile

Hi Chris! I logged in over there and am able to replicate… can you confirm you are on an officially supported install, and updated to latest? Any plugins or theme components you’ve installed recently that might be getting in the way?

If the above doesn’t ring bells, I would try safe mode next. Edit: I just tried safe mode on my phone with everything disabled and was able to post. You will want to work through the three options to try to narrow it down and then try to narrow it down to a specific theme or plugin.