I have a a dock site with many dock panels. The dock panels on the right side behave correctly in regards to the pinning, but the ones on the left side don't. If I unpin a right side dock panel, it puts it to the right as a sliding popout. If I click on the pin when it is popped out, it re-pins it back into position. However, with the dock panels on the left side, once I unpin one of the panels, it correctly puts it to the left side as a sliding popout, but when I attempt to re-pin the panel, it simply closes it back to the side and does not pin itself back again unless I drag it to a new position.
I am pretty sure, but can't confirm, that I think this used to work with 2018. But with 2019.2 and just updating to 2019.4, it still behaves incorrectly. I can't see any differences with the dock panels on the left vs the right. Even moving one of the left panels to right at runtime does not re-pin that panel.
Occasionally it does re-pin the dock panel correctly though, but 99% of the time it doesn't. I can't consistently find a pattern that makes it work.
In trying to create a demo for you, I created a new project and added left, right and center dock panels. However, it works fine, but so far it is a simple example as compared with my main app. So I'm at a loss to know why my main app isn't working correctly. Any ideas before I dig into it any further that might save me some time?