Repeating command blocks stop working after world template used to load world

A previously working world with command blocks was imported into a world template. When loaded all repeated command blocks stopped ticking.

This issue has affected two teams.

To resolve I recreated the template with a freshly run copy of the original map. The second template worked as expected.

In the non working copy I was able to fix the command blocks by data cloning them and placing them again. Also newly made repeating command blocks were not affected.

I was not able to reproduce the issue.