Low Pianus doesn't drop certificates when Carta the Sea Witch quest active

Description of the bug: (optional screenshot/video):When Carta the Sea Witch quest is active alongside the Badge of a Squad Member quest, only a bunch of Pianus screams drop instead of certificates.
What is supposed to happen?: Both certificates and screams should drop.
Where did you find and/or notice this bug?: at Pianus cave twice, once when I had the quests and another time with helping a friend who also had both quests active
A step-by-step guide to re-producing this bug (optional): Obtain both Carta the Sea Witch quest and the Badge of a Squad Member quest and then kill Pianus.

 

Unless I missed it, I didn't see an explanation in the thread, only that the quest should be reset to fix it, which I'm not sure is relevant for this.

When Carta the Sea Witch quest is active, Pianus drops as many screams as it would have dropped certificates, which I'm not sure is normal. Upon finishing the Carta the Sea Witch quest, Pianus dropped certificates normally. My friend had the same experience with the screams and after I had them forfeit the Carta quest certificates dropped normally again.

Unless it's simply that one is unable to obtain quest items for more than one quest from the same kill? The resulting amount of screams that it drops because of this is a bit questionable though.

 

Oh whoops, I see.

I wonder how you had the same problem with Zakum though.