Thank you for your answer aashishpattu and GoogleLover75 - I only now realized how rude I was. And CertifiedBlyndGuy: I hope you get well soon, and thank you for your outstanding work!
This is the procedure I got from the bughunters at Oneplus:
1. Go to phone dialer app and dial *#800#
2. Select the first option which says “oneplus Logkit”, delete history log
3. Click "advanced", choose "save log type", select all these...