Internet stops working when clients reconnect to network when using pihole

Hi all,

I seem to have an unusual issue when using pihole:

At first internet (with blocked ads) works for any connected computer. However, if I disconnect and reconnect a device to the local network the internet stops working on that device (all others are unaffected).

Occasionally even devices that weren't disconnected also lose their internet connection.

The only way to get it working again is to reboot the portainer containing the pi hole.

I followed this this tutorial on how to run Pihole using portainer and macvlan and this one on how to set up the router.

Does anyone know what could be the cause of this problem? Sorry if I've missed something obvious here but I'm a bit out of my depth and any help would be greatly appreciated!

I'm running on a pi 4b which also runs an OMV server.

debug log: https://tricorder.pi-hole.net/nx1m0e0d75