See this thread:
https://community.adobe.com/t5/premiere-pro-discussions/wrong-timecodes-when-exporting-srt-files-36-...
I am surprised there are not more reports of this issue. I did not test for drop vs non-drop frame, nor different start times.
Steps to reproduce:
1. Create a one clip sequence, transcribe, and create captions.
2. Export SRT.
3. Set Sequence start time (I used 10 hours)
4. Export SRT.
Result: SRT 1 starts at 00:00:01,200. SRT 2 starts at 10:00:26,976
Expected: SRT 2 should start at 10:00:01,200.
System info
Application: Premiere Pro (Beta) v24.1.0.2
OS: Windows v10.0.19045, RAM: 63.80 GB GB, CPUs (logical): 16