I'm facing a peculiar issue with my Mikrotik RB5009. I initially had it configured without any VLANs and all SSIDs (Default, IOT and Guest) were configured on the same network. I use Pi-hole (on a Pi3) but DHCP is managed by RB5009. The Wifi6 accesspoints run Openwrt. Randomly during either DHCP assignment, release or AP roaming, the devices would fail to connect. Logs indicated multiple connect and disconnect attempts. Even if connected successfully, they would show no Internet available. Pings to PiHole, Switches and APs (static DHCP lease) would fail multiple times. Sometimes things would go so bad that only restarting the mikrotik router would fix the issue.

I've since configured VLANs. Switches, APs and Pihole are on the Management VLANs/PVID. IOT Devices are on a separate VLAN. And Laptops, Smartphones are on a separate VLAN. I no longer have issues pinging any of the devices (VLANs are not yet isolated).

Any pointers on why I had been having ping issues without VLANs but everything seems to be working fine with VLANs?