Thank you for reporting this issue.
The fix has been applied to the JEM 5.0.2 and JEM 5.1.0 development versions. Event links are now copied to newly generated occurrences, and changes made from the root event are synchronized with the recurrence series.
Links can still be changed independently when editing a single occurrence.
Please test the fix in commit:
github.com/jemproject/JEM-Project/commit/6c49f7acedc5ada80085c5caea119d0dcea24a2f
Let us know whether it resolves the issue in your installation.
Thank you for helping us improve JEM.
