LTM pair, HA sync takes syncing from both LTMs

Env: Big-IP 4200v at 11.5.2 plain, in HA pair

This isn't really a problem, but some behavior I see concerns me (because it might be indicative of deeper issues).

Let's say I have a change on my primary LTM that I need to sync to the standby. I go to Device Mgmt | Overview, select the primary, select "Sync Device to Group", select "Overwrite Configuration", and hit Sync. Result is the sync status of the devices in the Device list (on the Overview dialog) goes to green, for both devices, and the "Configuration Time" for both resets to the current date/time -- all good.

BUT - the overall sync status in the upper left corner (next to the F5 icon) goes red, saying "Not all devices in sync". To clear that red status, I need to repeat that sequence, but this time syncing the standby back to the group, overwriting configuration. Then the sync status in the upper left goes to "In Sync".

Is this indicative of some issue with our device group or the device trust? I can't find any SOLs listing it as a known problem ...

thx!