Clicking on a tab in the list in the popup doesn't work reliably

[pmorch]

When I open the popup by clicking on the toolbar button, a list of tabs appears.

I expect that every time I click on a tab in that list it toggles its state between selected and deselected.

What I see is that most of the time it behaves as I expect, but sometimes clicking on a deselected tab only selects it briefly but it is the deselected again (from only that single mouse click). Sometimes clicking on a currently selected tab has no visible effect. I can't see that it gets deselected even briefly.

Run in an entirely fresh profile with only Multiple Tab Handler installed.

• Platform (OS): Linux
• Version of Firefox: 57.0.1 (64-bit)
• Version (or revision) of Multiple Tab Handler: 2.0.5

[pmorch]

I fact I just tried to move 3 consecutive tabs to a new window. But selecting three tabs was impossible for me with the mouse. Sometimes clicking on a tab made other selected tabs deselected too.

I had to use the keyboard.

Ubuntu Linux 14.04 using Unity