SublimeText fails to save file over sftp after apparent timeout

I am running lubuntu in a VirtualBox. In my file manager (PCManFM-Qt) I navigate to

sftp://myusername@myremotehost:/mydirectory

and open myfile.txt with SublimeText. I can edit and save this file without problems.

However, after some time passes (or for example after putting the machine to sleep), whenever I try to save I am greeted with the error:

Unable to save /run/user/1000/gvfs/sftp:host=myremotehost,user=myusername/mydirectory/myfile.txt
Error: No such file or directory

which does not seem to go away until after I restart the entire system. I cannot even re-open the file or any other file from the remote host into SublimeText; instead SublimeText just opens a blank file called "sftp".

I can still open these files with any other text editor on my system (such as gedit and notepadqq) so the problem seems to be with SublimeText.

Is there a fix for this?