We are experiencing a similar issue JAVA-3690 in production with MongoDB 3.6.9 and java driver 3.7.2. As per the JIRA ticket this issue is mentioned as applicable from 3.9 and above versions only. But we are experiencing this issue in the old driver 3.7.2 as well. We double checked that the fix is not in 3.7.2 driver code.

Please confirm if this fix is applicable to 3.7.2 driver as well. If not are there are any other issues which is resulting "Timeout waiting for a pooled item after " errors and all the threads are getting stuck unless the application is restarted.

Also is there an easy way to reproduce this issue ?