mouse lag after adding webpages to research folder

I’m getting bad mouse and/or trackpad lag after adding some web pages into my research folder. If the offending scrivener file is open it causes lag no matter what window I’m in. If the file is closed the lag goes away.

Would love to be able to use this feature, rather than just deleting the web pages. Any ideas? (Have restarted, reset PRAM and reset SMC already.)

This is on a MacBook Pro 2018 with High Sierra.

If anyone else has the same issue here are some solutions to try for a similar problem (typing lag): https://scrivener.tenderapp.com/help/kb/macos-troubleshooting/typing-lags

I tried all of these except for not saving to dropbox.

None of the suggestions worked for me. I deleted the added webpages and that fixed the problem. A shame I can’t save webpages to scrivener, but if someone finds this post and is having the same problem, these fixes are at least worth a shot!