Cannot point Nano 3 to Public-Pool

[MarkJelic]

My Nano 3 works fine when pointed to CK Pool.

But if I try to point them to Public-Pool, either the web hosted one (public-pool.io
or running my own version on my local Start9 server. In either case, the mining stops.

Is there a reason why Public-Pool seems to be blocked from the Nano3?