Systemd's automount units often fail after a suspend/resume cycle.  I believe
it occurs for units that are not mounted at the time the system is suspended,
but I'm not sure.  I've only tried this with nfs mounts, so it may only apply
to nfs autmounts.

Here's a log from such a failed unit:

  Nov 19 16:22:39 homelap5.WalkerStreet.info systemd[1]:
DWMedia-DWMedia7.automount: Got invalid poll event 16 on pipe (fd=71)
  Nov 19 16:22:39 homelap5.WalkerStreet.info systemd[1]:
DWMedia-DWMedia7.automount: Unit entered failed state.

Restarting the automount unit after the system resumes gets things working
again, so I've put the following script into /etc/NetworkManager/dispatcher.d
as a quick and dirty workaround:

#!/usr/bin/perl
#
# FixAutomount - Query systemctl for failed automount units and restart them.
#                This is needed, as suspend/resume seems to make them fail.
#                It can be invoked from a NetworkManager dispatcher script.
#
if ($ARGV[1] eq "up")
 {
  open (FAILED, "systemctl list-units *.automount --failed |");
  while (<FAILED>)
   {
    if (/\s+(\S+).automount\s+loaded\s/)
     {
      system ("systemctl restart $1.automount");
     };
   };
 };