To all the commentators saying "cut him out of your life" Have some compassion.

He's clearly struggling with reality and only just about managing. You turn towards, not away from, those who need help.

Its this sorta thing that gets schizophrenic people living on the street, where they become a danger to others aswell as themselves.

Psychosis often manifests as paranoia in the early stages, cutting people off at that point further isolates the vulnerable person and this actually accelerates their decline. In this case it seems that isolation during lockdown may have even been the trigger for OPs uncle.

If social isolation triggered it, how is more isolation gonna help?

Assuming, ofcourse, that this is what's going on, manic/psychotic people don't think like normal people - they don't have the insight required to correct their thoughts and behaviour. They can't help it. They are less likely to go "people are disagreeing with me, maybe I'm wrong" like a normal person would and instead go down a "they're brainwashed too, I can't trust them" sorta road, reinforcing the paranoid narrative, further ossifying the emergent trust issues and progressing the mental health decline.

Everyone I know with these sorts of issues, literally every single one, say the couldn't have done it without support when they come back around.