Unable to stack panels at the bottom of workspace

InDesign 21.4.1 on Mac Studio M1 Ultra Tahoe 26.5.1.

Pretty simple and annoying bug. I am unable to stack/group panels on my workspace. This only pertains to the bottom 1-2 for some reason. You are able to place more panels below 

I would confidently assume this is a reproducible bug. This has been present for the past few versions but I am just now reporting it. The workspace panel is one of the most important features for InDesign workflow and this is the second (albeit, not as annoying) bug I found that I didn’t even need to try to find… 

From the gif you can see it seems like the bottom 2 groups cannot be stacked. It doesn’t seem like it matters what panel you grab.