Re: I have two businesses linked to same user id and password... used to have choice of which bus...
I've checked our files to see if there's a reported case same as yours, Carlsonfloors. I've found no on-going issue.
You should be able to see and open your second company. This could be a web page issue that's caused by too much cache.
Let's isolate this. To start with, open QuickBooks Online using an incognito window. From there, check if you can see all your companies. If you can see them, go back to your main browser, then clear the cache. You should periodically clear them out to allow the browser/web to function without any issues.
On the other hand, using a different browser resolves issues like this (Google Chrome, Internet Explorer, or Mozilla Firefox).
You can get back to us if you need more help. We're just right here.