BUG - Source Clip Start Timecode can not be changed anymore (changes are not applied)

In Premiere Pro Beta 24.1.0 Build 42 I realized changing the source Timecode Start of an clip does not work anymore.

I import a video and go to: Modify -> Timecode , I change the Timecode from 00:00:00:00 to 10:00:00:00, I select "Alternate Timecode", I press ok. The clip Media Start dies not get changed, its still 00:00:00:00, it did always change in Premiere 22 and is a very important function when working with archive footage. This seams to be brocken now in Premiere 23 as well. It was working good in Premiere 22.