I have noticed that the system does not like it when the transcription screen stays open for more than 25 minutes. It seems like that annoying "lock screen" warning comes up after about 20-25 min. I think the system thinks we are idle rather than actively working. Saving does not seem to affect this. I hardly ever have this problem now that I reload back to the main file unit page after 20 minutes or so.
I hope that helps all those who are struggling with this issue.
Thank you for sharing this, Veronica. We are looking into this as possibility. Thank you for all your contributions as a Citizen Archivist.