Why this happens
Momence originally let you build class series without templates. When we later added templates for easier scheduling, we introduced new logic that only applies to series built from those templates.
If you’re editing an older, non-templated series, the system can’t link your changes to the newer template logic—so your updates won’t stick.
Fix 1 — Start fresh with a templated series (fastest)
Create a new series and choose the template that has the settings you want.
Verify the details (time, instructor, capacity, tags, etc.).
Publish the new series.
Delete the old series that wasn’t built from a template.
This fully aligns the class with the current scheduling system and prevents any future saving issues.
Fix 2 — Keep the old series and re-apply its settings
Open the Series (not the template) and click Edit.
In the options list, un-check every setting that’s currently selected.
Save to push those changes live.
Re-open the series, re-select the options you actually want, and save again.
Clearing and re-applying the settings forces the series to refresh its configuration and resolves the “changes not saving” problem.