Flashbang no longer carried alongside held item?

Or is it a bug?

Yesterday I was doing solos and saw my teammates were Resi characters. I obliged and selected Rebecca (I lost all my other Resi characters through cross progression as they were dlc).

Anyway, I was holding a toolbox which I found in chest, then went into a locker to make a flashbang. However, instead of carrying it as a secondary item, it dropped my toolbox. No matter how many times I’d try to pick the ‘dropped’ item, it wouldn’t let me carry both simultaneously.

Is this a change that I’m unaware of or is it a bug I wonder? It was the last game of the night last night for me so haven’t had a chance to replicate yet but was wondering if anybody else has had this issue?