Your comments

Good idea. Working on it.

That doesn't look right. Remove the "stratum+ssl://" part from "pool_address" in pools.txt and it should look like this:

[2018-10-19 22:43:27] : Fast-connecting to xmr.coinfoundry.org:3133 pool ...
[2018-10-19 22:43:27] : TLS fingerprint [xmr.coinfoundry.org:3133] SHA256:DyvyNe/NGgJqU6XVPQZz6yq29nrh//eAFu+dxHYSq8Q=
[2018-10-19 22:43:27] : Pool xmr.coinfoundry.org:3133 connected. Logging in...
[2018-10-19 22:43:28] : Difficulty changed. Now: 25000.
[2018-10-19 22:43:28] : Pool logged in.

Don't forget "use_tls" : true in the same file.

No, it was an I/O issue at the datacenter hosting this pool, which has been resolved by now.

No, of course not. I've just removed the troublemaker for now.