Hey there,
I vaguely recalled reading about a similar issue before, and I’ve found this thread: A Conflict Exists For -<module Name> while updating Record
The user noted that disabling “optimistic_locking” for the custom module resolved this issue.
Do note that, if disabled, you won’t see this screen for your custom module
(This screen is intended to show when two users are editing a record at the same time, to prevent conflicts)
Does this work for yourself?