Have multiple AP906 dotted around building each hardwired back to Switch via LAN port on AP. The switch is hardwired to a 2927AX.

I am trying to get the AP Central management on the 2927AX to manage the multiple AP906 however they seem to appear on the list as RED OFFLINE despite being able to click on the device and enter the device via the web management ports. Entering the passwords against the listed devices do not make any difference and at no point do the AP show as online.

All the AP906 are configured with the same SSID on 2.4g and 5g and only the channel differs between the AP906. The same SSID exist on the 2927AX again with the same settings with exception of the channels assigned.
The devices roam as expected between all the AP906 and even onto the 2927AX but for some reason they simply will not allow central management.

Any advice would be greatly appreciated as central management feature was primary reason for upgrading to the 2927AX router.

Worth mentioning that the AP management has been enabled on the AP906 along with the 2927AX.

I have now noticed that the AP906 are all appearing under the external devices section in the Central management. Some of these AP are directly connected to the 2927 and all are static IP on the same subnet as the 2927 so completely confused as to what is going on.