
There could be a number of reasons he changed his mind, some good and many not so good. I would first ask yourself what it was you saw in him and why were you interested to begin with. And then I’d have a conversation with him to push for a no-bullshit answer about what he actually wants, why he’s interested in you now and why he wasn’t before. And then make a decision based on the answers to all of the above.
to be fair tho he had a lot going on when we first met so it's understandable he wasn't interested in anything then and during the month he got on dating apps i had sort of ghosted him when he asked to do something he's smart and funny and honestly doesn't seem like the kind of guy that would play you but idk