I reported this bug (or something similar) in April:
As usual it's been pulling teeth to get any response at all from Shipstation support.
From checking into the tickets you mentioned, these appear to be different issues. As our escalations team wants to investigate all of these individual matters, reaching out to support with full details does continue to be the best course of action. Just because this individual issue is not yet resolved, does not change this fact.
Our product team is working very hard to make improvements that will help the most users, so unfortunately not every single piece of feedback brought to us can be made a top priority.
Your continued patience is appreciated at this time! I hope you're having a terrific week 🙂
This has been happening to us as well. Every time I deselect more than 1 or 2 devices in ShipStation Connect, all the devices end up disappearing completely. I have to sign out of ShipStation Connect on my desktop to reset everything and have them show up again. All of my devices appear once again and I'm in the same situation as before. I can't seem to deselect any devices without running into some sort of bug.