OP could compare a thread gauge to the female/internal threads on the block to find out. Or, more simply, do two things.
Throw a brand new nozzle in the block, grab it with pliers and apply strong, but not hulk, downward pressure (perpendicular to block) on the nozzle and see if it pops out. Don’t get too strong here because you’d just fuck things up if they aren’t already… you’re just trying to mimic filament pressure
Melt the filament off the ejected nozzle, clean it up (brass wire brush, perhaps) and do the same test as number 1
If #1 pulls out a new nozzle… Yeah… replace or rethread (good luck) the block.
If #1 sticks strong but #2 pulls out, replace the nozzle and hope it was just a shitty, undersized, nozzle. I don’t expect this to be the case, but eliminate all simple problems before trying to remedy a (maybe non-existent) larger problem. Troubleshooting 101