MAC: I am encountering a problem (proabably bug) when trying to select tabs on FF for Mac

[Elementari]

Hello,
I was trying to select multiple tabs to drag them to a different place within the tabs tree.
It worked well by usind SHIFT: I was able to select around 10 tabs, then drag them elsewhere.
However I then wanted to select a couple of tabs that were in various locations, by clicking only on those indiviual tabs that I wanted to drag, like for example tab 16, tab 19, and tab 25.
For this, I tried pressing any of the modifier keys, but none worked.
CTRL (Mac!) would trigger the following:

After pressing AND releasing "CTRL", moving the mouse pointer would cause the selection to select all tabs starting from the position of first click, to ANY position that my mouse pointer was currently pointing to:

I.e. it was like this:
Press down CTRL.
Click tab 25
Nothing seems to happen.
Move mouse pointer downward.
suddenly ALL tabs between tab 25 and the current position of the mouse pointer look as if they are selected. Pressing CTRL again (no matter if with or without also clicking on a tab), will not stop this behavior.
The only way I can stop this craziness is RIGHT click on a tab.
After right click, the weird behavior stops and no tab is selected.

I think this is a bug.