Relays responding to action in bursts hours apart

I have 20 standalone windows relays, 17K endpoints running BigFix 10.0.9 on Windows Server. I 've noticed that when submitting e.g. a blank action to all 17K endpoints, all endpoints on BigFix server respond in a few minutes, then an hour and a half later most of my other endpoints on the 20 relays show up, and finally another hour and a half later the rest of endpoints on the remaining relays.
In another blank action run, BigFix server endpoints respond in a few minutes, then a majority of them respond from the other relays in 40 minutes, and one relay responded 6 hours later.

Is this normal? If not, what could be causing this behavior of delays before starting the action on the other relays.

Regards … Leslie

The most likely cause is that downstream notification traffic from the root server to the relays is blocked.

The notifications to clients are sent down from the Server & Relay on UDP/52311 ; but the notification to relays are sent down on TCP/52311 (TCP, not UDP) from the Root Server / Parent Relay to Child Relays.

If that notification traffic is blocked, the child Relays won’t see the action exists until their gather interval (6 hours by default), or if Command Polling is enabled then the next time they perform a Command Poll.

There were a few relays that could not be reached by tcp/52111 from the BigFix server. I’m getting that addressed now. Thanks.
Does the server target the relays serially or in parallel? ie. Does it push out the notification one relay at a time or does it do it in parallel to multiple relays at a time? Trying to figure out why it waited as most of my relays CAN to communicated to on tcp/52311 from the BigFix server.

Regards … Leslie