Reference variable is getting "stuck" in a variable list after deleting Border in UserWidget

The recent problem I’ve experienced with UserWidget.
I create a brand new widget, then add a border, and enable “Is Variable” on its name, after that I select “Wrap with-> Border” (also enable “Is Variable”), and after that on a first border I select “Replace with Child”. This one border is now deleted and being replaced by the fresh created, BUT in my variables list I see now two reference variables for both borders, even desprite the fact the first one doesn’t exist in the Designer.

The question is how to remove those variables from my variable list?

Does it persist after restating the editor?

Yes, it is. I’ve checked a binary file, it basically becomes stored in a blueprint itself after saving

Can you try doing this in the affected widget?

307182-annotation-2020-07-14-145918.jpg

Sounds a bit like this fixed bug:

Thank for your help and reply, but, unfortunatelly this advice did not work, saying that all variables are in use.
I also have checked on another machine. While I could recreate the problem, it turned out that after the Editor restart, all retained reference variables are being cleaned on the next start normally.
On a computer of my colleague, which originally got this problem just recently happened the Editor crush, and only after that crush and further restart those retained reference variables have gone as they should. So I guess the problem is solved now, at some way at least.

Thanks for the update. Hopefully this is an isolated scenario.