Just a PSA: for anyone using a MikroTik router, using it for their DHCP server and are having issues with their devices not using Pi-hole.
If you have set the IP of your Pi-hole as the DNS server and are seeing entries in "dynamic servers" then the router is using your ISP's DNS server causing it to bypass your Pi-Hole.
You need to go to the interface that is supplying your internet connection (PPPoE client, DHCP) and turn off the option "use peer dns".
This will disable dynamic servers and route everything to your Pi-hole.