DRS 20 Bug? Change nested Timeline timecode - offline error

In DRS 20, when a timeline is nested inside of another timeline (master) and the nested timeline start timecode settings are changed to reflect the timecode within the master timeline, upon saving the new start timecode the timeline becomes offline.

This did not occur in the previous version(s) of DRS.

As far as I can determine, the only way to correct this issue is to replace the offline timeline with the updated timeline from the media pool.