Ads galore on devices after installing. Is this to be expected? Does it need to run a few days?

You've got IPv6 support upstream and the router is configured to auto assign a bunch on the clients via IPv6 auto discovery (IPv6 address, IPv6 gateway, IPv6 DNS server(s) etc).
Am not proficient enough with IPv6 to give you a good configure advice ... wait for someone who does.
And have a read here as well: