Ok after some captures I detected the exact same issue bellow   https://www.cisco.com/c/en/us/support/docs/wireless/aironet-3800-series-access-points/214491-arp-responses-for-default-gateway-ip-add.html         ... View more

Try to capture on the Meraki dashboard a .pcap file from a device with issues and see if it has dns requests without responses.   Then try to capture the requests on your dns server and look if the requests came in.   In my case, the dns requests take about 5 minutes to came in and then the device can connect. ... View more

Hello GJ1,   I'm having this issue today for SSIDs that are on bridge mode, but my GUEST network that is using NAT mode, it's ok.   Also, I'm having this issue only for Android devices.   A capture using logcat indicates that the Android devices are setting a wrong DNS ip address.     ... View more