Nginx domain resolution not working when exit node enabled

Like the title says:

Tailscale is installed on unraid (local) and on a vps. both act as an exit node but only unraid is set as a subnet router. nginx is running in a docker on unraid with fixed (separate to unraid) ip. on cloudflare i have a wildcard configured to *mydomain.ch which points to my nginx local ip address. this works as long as i:

- enable tailscale without exit node (use tailscale dns is active/ not active --> both work)

- enable tailscale with vps-exit node (use tailscale dns is active/ not active --> both work)

- enable tailscale with unraid-exit node (use tailscale dns is inactive!!)

it doesn't work when enabling unraid-exit node with tailscale dns active.

magicdns is disabled because it broke my network at some time (maybe user-error but idk)

no nameservers configured in tailscale admin dash

what is the upside of using tailscale dns/having it active?

how can i use the adguard instance to filter dns when on the go (connected smartphone to tailscale?)

thanks in advance for ur help..