Slow to load page

Why is K9 suddenly got very slow at opening on my S10+. When I delete anything too the page goes blank and takes 20-30 seconds to come back with the existing emails.
Anyone else got this problem?

What exact version of K9 do you use?

5.807 is the version i use

And when you say “suddenly” has there been a version upgrade of K9 done around that time?

Maybe you should give version 6.000 a try which has released recently: