In addition to Vi.'s answer, this might also be related to the DNS timing out (or maybe not being configured correctly in the first place): Forwarded connection refused by server: Administratively prohibited [open failed].
In such case, you might be able to get around these DNS issues by something like
Otherwise, as Vi. points out, indeed, sshd_config(5) has the following wording in regards to a possible blocking of TCP:
Specifies whether TCP forwarding is permitted. The available
options are ``yes'' or ``all'' to allow TCP forwarding, ``no'' to
prevent all TCP forwarding, ``local'' to allow local (from the
perspective of ssh(1)) forwarding only or ``remote'' to allow
remote forwarding only. The default is ``yes''. Note that
disabling TCP forwarding does not improve security unless users
are also denied shell access, as they can always install their
Ports above 1024 generally don't require root privileges on most systems -- so, potentially, you might be able to run your own sshd or proxy on an upper-level port (you could even ssh back to your home machine, and do a secure forwarding of a single port that way).