Pi-hole doesn't resolve the right DNS

Hello my pi-hole runs on docker at my Synology NAS.. sudenly my main DNS ip who is my pi-hole ip doesnt resolve my ip And its goes through my secondairy ip 8888 from Google.. So if i delete my secondary i don't get any internet. If i log in my front panel i see my devices showing up using pi whole... what causes thé problem?

Please send us the token generated by

pihole -d

or do it through the Web interface:

Hey Jfb thanks for the reply: https://tricorder.pi-hole.net/i8z7d8r95b is this what you need ?
I reinstalled my pihole but saw it could not load the docker it stopped..... And the line in the log proved it:
[✗] DNS resolution is currently unavailable

But i think now i fixed it again cause my pihole blocks the basic adds again ... cause i think the firewall on my synology blocked the dns ?? Could that be the cause? What do you need to set open to get my firewall secure cause i did a custom setting on my synology.