Slow message delivery

Good afternoon.
After switching to sametime 12 and reaching the number of connected users of about 1000, messages begin to be delivered very slowly - delays of 3 minutes.

We do not observe any physical load on any of the nodes.

Server SameTime12:

Server mongodb:

Server balancer:

Please tell me where the problem might be? What needs to be checked?

@Moises Romero Barraneche

this is best handled by opening a case with support