@RTMC The main thing you will want to look into is signal. You will need enough overlapping wifi signals between APs. I usually do wireless site surveys... When 2.4ghz hits -70, I usually put another...

@Alam0786 Manually set your dhcp server DNS section to google dns (like you did the ap). Disconnect and reconnect to the wifi on your device and see if it works?

@Alam0786 I use WhatsApp all the time with a full Omada stack, with no issues. Are you using URL filtering? Which DNS servers are using?

At this point, I know you can configure APs in standalone mode with your phone APP. Is there going to be StandAlone Configurations through your phone with routing and switching? Or at least a Mobile...

@jbl-tom Could try the ARP list. Firewall> Anti Arp Spoofing> ARP List That may help.

@RobertMEF 10 seconds is my starting point. It's been a good number for me so far.