Hello @0ber0n
Just looking at the screenshots you have provided i see a number of potential issues that need to be addressed. The Q&I time for the DDB is very poor and a newly scaled partition will not address this.
It also seems that you are moving your clients between the old and newly scaled DDB ( i am basing this on your baseline being so small for the old database partition ) and this is bad practice.
When a DDB scales you expect all old clients to stay and keep going and new subclients to use the new. Doing this removes the hit to storage created by rebasing your data.
I would recommend raising a ticket to review the health of your environment. I would guess your disk is unhealthy and this would be step one to check but support can help answer that first.
Kind regards
Albert Williams