F5 BIG-IP Device Groups use a concept called "config-sync", where one device pushes its configuration to the rest of the group.

Here’s how it works:

Only the device that made the change (i.e., has the highest commit ID) is allowed to initiate a config-sync.

Attempting to push configuration from a device that did not make the most recent changes will result in a sync failure, because the system wants to prevent older configurations from overwriting newer ones.

Thus, only from LTM-B is the device eligible to initiate a config-sync