I know the documentation does say that the Print To settings are user specific and browser specific. However, for one user on one browser after setting the default printer every time they come back in the settings are back to Always Prompt.
How can the default printer be set?
You are absolutely right that the print to settings are user and browser specific. With that behavior being experienced for a single user, and not account wide, my initial thought process points to either a manual change or a browser issue. Keeping that in mind, I would first recommend to clear the browser's cache and cookies, logging back into ShipStation, to make and save that change to the Print To default from the printer settings.
If you continue to see that behavior afterwards, I would want to get one of our agents from the support department to check into it so that we could do some follow up testing into the backend of the account.
Thanks so much for turning to the community for assistance! I hope this helps! 🙂