Bonjour Service not working on 5GHz network

Hello all,

I have a D-Link DIR-882 router with both 2.4GHz and 5GHz wifi enabled. After about 1 day all the bonjour services will fail on the 5GHz wifi but still working on 2.4GHz (i.e. Airplay devices are not able to be found, printer not found (with IP ok), smb services (with IP ok)). I have tried to install mdns service but that does not resolve the issue.

WMM mode are enabled on both channel, Mode in Access Point, isolate clients is disable.

Is there any way to solve this problem?

Many thanks,

Any ideas on this?