Samsung DV328AGW Dryer heats for 10 seconds then shuts flame off

[attim0de]

I was having issues with clothes not getting dry and completely cleaned the ducts which seemed to help, but not fully resolve the problem. The dyer is a Samsung DV328AGW with propane heat. I cut a viewing hole in the front and sealed it with a clear window to observe the flame and found that the heat was only running for about 10 seconds. The dryer continues to run without issue once the flame shuts off and the flame will come back on once every minute or 2.

I've replaced the following to try and diag:
- Thermistor (OE Samsung part)
- Flame-out sensor (2X Amazon parts)
- Coils (Amazon part)
- High temp sensor (on heating barrel, Amazon part)
- Ignitor (Amazon part, seems to be working fine)

After swapping out all of these I'm still getting the same result so I'm now at a loss on what it could be. I guess it's possible that a new replacement could be bad, but so far swapping all of these sensors has changed absolutely nothing. It's my understanding that the flame is supposed to run for 1-2 minutes before shutting off, is that correct? The clothes are drying better due to cleaning the duct but a load of towels for example still takes 2 cycles so it seems that something is still off.

Here's a video of the flame:
https://youtube.com/shorts/sqAFPEgAB...JnYi6KdHH2h2EW

Any insights are appreciated