Sequence in and out points randomly change when opening projects

[MartinHuntford]

• Issue – I've been working on a number of longer projects recently and I'm noticing that everytime I open the projects, the IN and OUT points that I had set on my sequences have randomly moved. Sometimes the IN point will be a few seconds later. Sometimes the OUT point will be a few seconds earlier. The duration of the jump is never the same each time.  
• Steps to reproduce – I have a slate at the start of all my sequences, which we use to make internal notes and caveats when providing WIPS to client. When reviewing internally, we don't need to use these, so I set an IN point on the sequence at the begining of the edit proper. And an OUT point on the final frame. These points do not move while we're working on the edit. I'll save the project for the day, and the next day when I open the project, one or both of these IN/OUT points has moved a few seconds and I'll have to re-set them.
• Expected result – IN/OUT points should not be moving unless I've moved them. 
• Actual result – IN/OUT points are moving of their own accord.  
• Adobe Premiere Pro version – V 25.4.0 Build 99
• Operating system – Windows 11 Pro 25H2 Build 26200.6899
• GPU driver version (Windows only) – NVIDIA Studio Driver v581.57
• Comparative information helps us understand more about when the issue occurs: 
  • Does it affect all projects or only some projects? - All Projects
  • Does it affect new projects? Yes
  • When did the problem begin? Approx three weeks ago

[Bruce Bullis]

Strange! 

Where do you set the in/out points for the sequence; in the Program Monitor, Timeline, or Source Monitor? 

You say the problem began ~3 weeks ago; did you change PPro versions around that time, or were you using 25.4.0x99 before and after the strange behavior began?