so, there was another thread a few weeks back where some users seemed to have a similar condition, but they were using the shelly binding. So you may want to give it a read it offers some tips as well.
Since you did not mention that binding in your list, we will assume you are not using it.
as for how to tie a thread to a binding.
you could trigger a support bundle.
cli dev:dump-create
Then install something like eclipse memory analyzer and open the dump file and run the analysis and poke around and you should see what binding is making all those requests or at least give you more insight as to what is occurring.
You do have memory constraint as you can see from your resource print out
free memory is now low and yes very likely from all the threads in a timed_waiting state