I’ll try clearing just the history. Thanks for the tip.
I’ve seen a problem like this before. I posted about it here in April 2023 ( Should kRUNNER be a application runner first? ). Maybe this isn’t the same problem we are talking about here, but to me it appeared related.
I update to the latest Kubuntu release whenever it comes out (twice a year) and I have the backports enabled, so I am always very up to date.