I mean if her rallying for Biden means campaigning for him, I honestly think that she particularly has every good reason not to do that. Tlaib is a Palestinian American, and Biden has openly contributed billions directly to Israel's ethnic cleansing of Gaza, going so far as to bypass congress to do so, all while he and nearly every other Dem continue to refuse to acknowledge that Israel's actions constitute anything "messed up," much less full-on genocide.
I cannot stress enough that if, in the face of Biden's continuing contributions to the genocide of her family's country of origin, it is an ethical impossibility for her to publically endorse him for a second term, that is completely on him, not on her.
I'm sure there's an in-depth reason for it, but there is one that scrapes Old Reddit, instead of the main site, and it works great for me (Stealth on f-droid). There's also RedReader, a client that was allowed to keep API access because of it's accessibility features... which I guess Reddit just couldn't be bothered to implement into their own app.