I can't reproduce this. Sounds like your control key is failing to activate sometimes when clicking as if you were holding down just shift.
Do you hold down ctrl, hold down shift and then click or do you try to hit ctrl + shift and click all at the same time? If the latter, the chances of it not working correctly are higher.
I am afraid you hit the nail head - my keyboard ctrl is a little bit tired and kbd probably needs replacement.
There have been also occasions when ctrl+c didn't work.
I just didn't know there might be another shortcut so similar.
I try to keep in mind to provide later feedback. (but as well if there isn't any reply in 2 weeks this was a solution)
My posting was initiated because this flaw also deleted all previously opened tabs history.
Reopening Opera didn't include previously opened tabs.