Thanks for the pointer to Nest. I had the same issue here. Turns out I was still using Nest WWN API which was deprecated Sept 29th 2023. This caused OH’s memory to fill up with HTTP threads trying to reach the deprecated API, and eventually OH to get OOM.
Although ultimately of course I should switch to the new API, this is a rather harsh way to find out about it. The Nest binding could have handled WWN API connection errors in a more graceful way…