Hello @windows2025 (no harm in using your real name, just saying! 
), and welcome!
It looks like your question was posted in the wrong thread. Ideally, you should have started a new topic for better visibility, as this post isn’t related to your query.
That said, regarding your question, a few important checks are missing:
- Are all 31 devices visible in BigFix Web Reports?
- Does your ATREDS** computer group correctly show all 31 devices in the BigFix Console?
- Are all 31 devices subscribed to the “Patches for Windows” site?
- Are all 31 devices running Windows OS?
- For the device(s) not showing relevant content, if you open the device in the Console and check its relevant fixlets, do you see any matching patches based on your filters (e.g. Source Severity = Critical, Category = Security, and Source Release Date)?
If you go through these points one by one, you should be able to identify the root cause.