Hi fanisatt & leszek
Thank you both for your replies.
I want & need to offer you both, especially you leszek, my humble & deeply embarrassed apology for having wasted your time. I am simply an idiot, & here's why.
The problem, the curse which has frustrated & annoyed me for the past couple of years, now in two entirely different KDE distros, is now solved. The fault, the blame, lies 100% with me; not with KDE, Plasma5, Klipper, Clipboard, Mint, or Maui; not with my decision to reuse my /home partition when i installed Maui over Mint... it lies utterly with stupid me.
This morning, whilst i was looking for something else, pure serendipity lead me to stumble over THE root cause, & hence the solution. All it took to eliminate this aggravating problem, was two mouse clicks. Now, there are no more 4-second popups. All this time i had been looking in the wrong places, at the wrong things, & blaming innocent software & settings.
The actual root cause was a setting i'd either not previously noticed, or else never correctly understood, in Cairo-Dock, specifically in its Clipboard History settings. In a subsection is an item called Actions, & it was active. I simply then deactivated it. Applying that simple but huge change solved the problem!
I am now very pleased & relieved, but also very embarrassed. Sorry to you both, & thanks to you both for really trying to help me.
Thank you both for your replies.
I want & need to offer you both, especially you leszek, my humble & deeply embarrassed apology for having wasted your time. I am simply an idiot, & here's why.
The problem, the curse which has frustrated & annoyed me for the past couple of years, now in two entirely different KDE distros, is now solved. The fault, the blame, lies 100% with me; not with KDE, Plasma5, Klipper, Clipboard, Mint, or Maui; not with my decision to reuse my /home partition when i installed Maui over Mint... it lies utterly with stupid me.
This morning, whilst i was looking for something else, pure serendipity lead me to stumble over THE root cause, & hence the solution. All it took to eliminate this aggravating problem, was two mouse clicks. Now, there are no more 4-second popups. All this time i had been looking in the wrong places, at the wrong things, & blaming innocent software & settings.
The actual root cause was a setting i'd either not previously noticed, or else never correctly understood, in Cairo-Dock, specifically in its Clipboard History settings. In a subsection is an item called Actions, & it was active. I simply then deactivated it. Applying that simple but huge change solved the problem!
I am now very pleased & relieved, but also very embarrassed. Sorry to you both, & thanks to you both for really trying to help me.