Took awhile for me to notice, but trying to making changes to the Pane Groups is different now.  Left Clicking no longer drags one out to a separate pane as it used to. Looking for some more info, the latest avail on YT is The WP Guru and is using 4.21, and that's key thing he's doing.

Tried Alt drag, etc. and no go. In fact, you no longer get the double-direction arrow when over the divider line.

Right clicking menu doesn't help much, nor does having TWO options for the Documentation help. Seems to me having an Editor with an arrow, but that only gives you the Documentation option is a mistake or incomplete.

Anyone?

Click hold and drag to move the panels, try using the left click, double cliking for the others

Click and drag the pane should move it to another group, if you drop it into the tab well of an existing one, or create a new floating group, if you just drop it away from an existing well. For a floating group dragging the top bar will move all the panes as one. You cna lso use a right-click in the tab well of an existing group to add a new pane to it.

I get the right-click menu, but all Left Click and dragging the pane does is sit there. For me on main system anyway, so something isn't getting along.

In the Panes Groups, I no longer get the double-direction arrow when over the divider line either.

I checked on the Laptop, it's DS 4.24 as well, but Clicking & dragging the Panes is working, slow but working. I still can't move the Menu groups nor get the arrow indicator.

They both use a Logitech Ergo M575 trackball. Only difference I can think of is the Laptop is a slightly earlier driver version than main system.

Boxx system using:
https://marketplace.logi.com/releasenotes/optionsplus/en#1.93.755983%20/%201.93.755984

Might that be a starting place to look?

You might want to reinstall your mouse software, or go into your settings for the mouse and make some changes there.

Is Window>Workspace>Lock Docking/Undocking checked? Though that shoildn't disable resizing the groups.

I'll look.

It was ticked and and unchecking allowed them to be dragged off. The Menu dividers still don't give any indication when over them though.