Azcapa's Medallion -- didn't increase my medallion slots

So I had the Azcapa's Medallion drop and my medallion slots were already full. I clicked on it and Alva comes but I noticed that it does nothing.

Previously when my slots are full there would be a warning that specified as such but for this one in particular there was none.

Did the same thing my medallions were 3/3 didnt notice picked it up and didnt get anything or a warning it was full and lost it :(

Just happened to me as well. F me I guess. :/
Beat the architect, medallion increase medallion slots was dropped. Alva yoinked it and now it's gone and I'm still at 3/3.