Hello,
Ok, lots going on here, lets start looking at local comms and get that sorted before moving on to remote issues.
The following error from the GUI is curious:
To locate a running suite Cylc uses the contact file (located in ~/cylc-run/<suite>/.service/contact).
This message suggests that CYLC_SUITE_HOST is set to localhost in that file which, if true, is likely the issue. I would expect this to be set to the FQDN for that host (i.e. hostname -f).
Could you check the contact file of a running suite to see what CYLC_SUITE_HOST is set to as it could be to do with host self-identification. Also check the output of hostname and hostname -f.
Typically these two should match:
$ hostname
$ python2 -c 'import socket; print socket.gethostname()'
As should these two:
$ hostname -f
$ python2 -c 'import socket; print socket.getfqdn()'
Oliver