I don't know if it's necessarily shadowbanning, there was a change a couple months ago to defeat some of the trumpcoin shills that broke the follow / homepage posts flow. A buch of other ppl I follow were in the same boat as you.

That, and when you "install" Gab as an app via Chrome-based browser (think fancy fullscreen mode), you lose the ability to refresh, so I see like the last hour of posts then it recycles or shows me crap from two days ago. There's def a technical problem there, but not sure when it'll be fixed.