Officially unknown, yeah, but the main suspect denies it’s him. What’s interesting is that the way he denied it (“We are all Banksy”) could mean everyone or just him and his closest associates in a collective, giving any one of them, including him, the ability to deny it.
I can see this being stirred up by Russian influence. And even if it isn’t, it’s a dangerous time for this to happen. Georgia could well be on Putin’s to-do list whether he succeeds in Ukraine or not.