Many times I found this form of tense avoir + être au passé + participe passé du verbe, for example :
il a été happé
but I don't find it as a French tense.
Do you have any idea what it is?
It's 'le passé composé d'un verbe conjugué à la voix passive' (passive form).
Full details for 'happer' here.
"il a été happé" = "he has been caught" or "he was caught" depending on the context