I do have the problem on three devices, that the mouse clicks are not working properly anymore. Instead of a single click, double clicks are executed. Is this a big or a feature? Produce a lot of hassle.
Maybe the problem is caused by the worn micro switch in the mouse. I ran into this situation many times before after a mouse had been serving for a long time. Have you checked with another mouse?
+1
Of the dozen or so mouses I used in the last decade at least 10 were retired because of this.
Did this just start after previously executing only single clicks?
You might also check Settings/Input Devices/Mouse and make sure it’s not set to single-click to open files and folders. Just in case.
I have run into that doubleclick problem.
Replacing the mouse fixed it.
About the same experience 
Good acting.
I had "fix"ed twice on a mouse with this problem by cleaning the reed of the micro switch. It’s just too tedious.
Rebooting into Ubuntu and Windows fixes the Problem. So I see this as a OpenSuse issue, as it exists with 3 Computers.
Then, MAYBE you could play with the “Double click interval” time to see if it helps.
Supposedly you’re with KDE Plasma, the “Double click interval” lies in “System Settings” → “Input Devices” → “Mouse” → “Advanced”. See also here for a screenshot: https://forum.kde.org/viewtopic.php?t=122085
Other than that, I am sorry but I could not be helpful any more. Good luck with other’s advice.
Is it a wireless mouse?
I have had problems like that come and go on more than one wireless mouse, usually some signal interference from some external source.
In the offices of a few of my customers years ago, I found that a passing car would cause random clicks (took a while at first to relate it to cars going by in the street outside, but once I noticed the relationship, it was easy to confirm).