Please follow the below steps.
> Go to Lightroom > Preferences(In Mac)
Edit > Preferences(In Windows)
> Click on the General tab
> Uncheck “Show ‘Add Photos’ Screen”
> Restart Lightroom
Let me know if this helps.
Also,please confirm the version of Lightroom and operating system you are using?
Thanks, this worked for me!!! Every click resulted in Lightroom pausing, pretty much unusable. After this change, performance is back to normal.