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

This is still happening to me!
I have been stuck on 5 slots and I have killed the Architect more than 7 times now and it still hasn't dropped again since last time he dropped and I clicked on it while my slots were already full. No warning no nothing. It had just dissappeard and I couldn't increase my slots since.

This has also happened to me. I clicked on the medallion when I had 3/3 slots full. Now even when I am not full, it's not picking up that specific medallion.

This is still happening to me!
I'm stuck on 3 slots. I've used the medallion several times, but the number of slots doesn't increase beyond 3.

Im also having issue with sixth medallion slot. Im stuck with 5 slots and have used quite a few +1slot medallions but not getting anymore capacity. Edit: Now i got 6th slot but i have no idea why it now worked.