Since at least Qt Creator 4.13.0 it's not possible to call a recorded vim macro (recorded with q<register>) with the key @. It worked well before.

Typing :normal @<register> still works

Maybe there is a conflict with the @+mouse click feature ?

EDIT: So it seems that the bug happens only on french AZERTY layout (or similar?). Because to type '@' we have to do ALTGR+0. But ALTGR trigger the "Go to symbol definition in a splitted window" feature.