I suggest you should probably open a new topic, and include some snippets from your clients’ logs. We would probably need a lot of the same info that Support should be asking, such as messages from your client logs for relay selection, and how frequently they are reporting, along with whether host-based or network firewalls are blocking any of the traffic.
There are several different types of “not reporting” clients so the diagnostic steps may vary.
I’ve just put together a post with general information for several common diagnosis items that I think may be helpful at Troubleshooting Client Reponsiveness