I can't log into quickbooks online app. It tells me "unable to sign into this company, please try another one". I can log in fine on the website, makes no sense

Glad to see you in our forum, @kevindelappe,

I have a couple of suggestions that you can try to get the application it in working order. Make sure the it is updated to ensure all critical patches are downloaded.

You can also try uninstalling and reinstalling the QuickBooks Self-Employed application to resolve installation corruptions. It will also help reset the application data so it functions properly.

However, if the same thing happens after doing those suggestions, I recommend reporting this to our Support Team. They will create a ticket for this problem and escalate it to our engineers for review. To get our support, check out this link: Contact QuickBooks Self-Employed Support

In the meantime, access your account temporarily on a supported browser while we're looking into this.

Let me know how it goes, as I want to make sure this is resolved for you. I'm always here to help. Have a nice day!