Apps always reset to infinite text drag delay

Hello, I am not a developer but my Mac has such a serious problem I am desperate for help. After some time of being open, all text applications lose the ability to drag selected text. This may happen after a few hours or a few days. Relaunching the affected apps fixes it by setting drag delay to normal.

This problem started some years ago in version High Sierra and I have been living with it since then. I had set a custom drag delay from earlier versions by saying
Code Block
defaults write -g NSDragAndDropTextDelay -int 100

This worked until High Sierra when the current trouble started. Now I am running the latest Mojave. The problem is obviously in my preferences files but which one and can I delete the offending setting with XCODE PLIST editor?

Thanks for any help.
Apps always reset to infinite text drag delay
 
 
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