Could you provide at least 1 of your m2t file specifications?
What are your system specifications?
- CPU
- Data Drives (HDD, SDD, NVME)
- Memory
I don’t think it’s an issue of how many tracks, rather more or less the amount of memory that is being used, to data drive handling of files while using other programs. I don’t believe there is a simple answer to your questions. What this forum is lacking is people reporting back what works for them, and all specifications of their system and files used.
It has been recommended quite a few times in this forum to just simply restart your computer, and only use Shotcut, with no other applications.