Editing document on local device; same whether .odt or .docx; tried with wifi on or off.
When editing text, unusable delay between keypress and screen update, 10 - 17 secs.
Can’t see a version number, but the hashes are:
Online GIT Hash eb73aa348
Core GIT Hash e90143624dba
iPad Pro running iOS 15.6.1
Problem solved - it was multiple instances of the app which caused the issue (something like 6 to 12 instances).
(It was the iOS app on an iPad, but that app had become a web interface - I think, from memory - previous versions handled everything on the local device. I may be mistaken.)