I run a number of business X accounts which are post-only.
The very second the US election got underway all of our accounts started to heavily promote right-wing political content. Even though we specifically said when we signed up that we aren't interested in anything like that.
This happened to me on imgur, i explicitly filtered out politics but once the election got underway I started seeing it everywhere (except in imgur's case it was left-wing content). I turned off the politics filter and then turned it back on and they vanished for a time but then slowly leaked back in. If i reset the filter every week then i could keep political related content hidden for the most part.