Stepstone gone from mailbox (after force close and abandon match)

My unclaimed items from the mailbox are gone, only exception is the Royal War Crate.

What I suspect did it:
I managed to phantom dagger TP to a goblin bugged into terrain.
Alt+f4’d the game, it failed to shutdown properly so I had to relog into my windows profile.
Reconnected to the match, still couldn’t get out.
Abandoned match from the ingame menu.
Noticed my mailbox items are gone after the next match ended.