If using a SIP account, disabling STUN and/or Rport (or enabling it, depending on its current state) could help.
Please open settings -> Preferences;
click on Accounts;
select your account from the list on the left;
click on Advanced;
enable or disable STUN and/or Rport;
save the changes and try to recreate the issue.
Try different combinations for best results.
Also, please try using TCP transport for your account if your provider supports it.
