Firefox Portable 115.4.0esr Drag Drop Shortcuts Bug

FF Portable 115.4.0esr (but also going back to at least 115.x.x if not older versions) Win7SP1 x64

For various purposes, I used to drag 'n drop shortcuts from FF URL bar, into folders. That stopped working after a FF update. Researching it, I found it worked again by launching FF portable with -no-deelevate on the shortcut to it.

That worked for (months?) and then after another update, could no longer drag and drop shortcuts into folders again. Researched it some more and found this could happen if Windows UAC was disabled, which I had done on this old system because it was interfering with a lot of older apps running correctly.

Enabled UAC, and could once again drag and drop shortcuts from FF URL bar to folders, but as expected, UAC then caused too many problems for apps. Decided I could more easily live without drag and dropping shortcuts so I disabled UAC, and rebooted... and now I can still drag and drop shortcuts to folders.

It doesn't make sense. Toggling UAC on and then off again, (rebooting both times) fixed dragging and dropping shortcuts into folders. Any idea why, what the underlying issue was?