Router is Vigor2762. Wifi doesn't reach the whole house so I've run a network cable under the floor to a VigorAP903 which is managed through 2762 Central Management. AP903 is operating in AP mode. All mobile devices are working correctly. We have two wireless printers. Both have been printing and scanning extremely slowly since installing the AP903. Printer wifi status report passes all tests but states:

*Multiple network names (SSID) that match your entered network name (SSID) have been detected. Confirm network name (SSID).
*A router/access point channel conflict has been detected. If you have problems printing or scanning, improve your wireless network environment.

Re the first error, it is correct both the 2762 and AP903 have the same SSID because the AP is operating in AP mode.

Re the second error, both the 2762 and AP03 have channels set to auto and the channels selected are different. If I manually set the channels to different ones the slow print/scan problems persist.

I have been able to resolve the problem by inputting the printer MAC addresses into excluded devices in the AP903. But surely 2762 Central Management should handle this? I have a wireless PC next to both printers so is within range of both 2762 and AP903 but the wireless PC works correctly as do all other mobile devices. This problem only affects printers and it affects both my wireless printers.

Is there some setting I am overlooking?

Two thoughts
1 - Ensure "Isolate members with IP" and "Isolate 2.4 and 5 band" is disabled on both AP's
2 - Create a separate and different SSID on each unit so the printer only attaches to that AP.

I have a AP912 and an AP903 and encountered similar problems with some iot devices and my HP printer which seem to get confused with what they are/should be talking to, creating separate SSID's and only allowing the printer onto one AP sorted out the problem.
They are able to support 4 SSID so I have one SSID common to both AP's on both 2.4 and 5 using Band Steering to control switch over and that is fine with phones/laptops etc. Then a separate SSID for each AP and bands, which I only use when devices get confused, like printers and some smart plugs/devices.

As for "Central Management" sorry but I avoid it totally, it has caused me more problems than it is worth!