Hi Kosta,
I do not know if this is FlickType related or not.
Last night after I updated FlickType, I was typing in different fields, and I tried filling in the fields in a new email. After I was done typing I hit cancel and then delete draft. My iPhone 8 screen went black and the phone totally locked up. No matter what I did, I got no response. I helm the power and home buttons down for 30 seconds but it would not reset. Finally, I plugged in the charge cord which eventually restarted the phone.
Since then I haven't had any problems.☹️