Hi Just1,
Connecting with your clients in QuickBooks Online is mutually beneficial, as you'll be able to easily get your bookkeeping work done while saving your client's time! I know it's essential to be able to accept your client's invitation, and it sounds like you've tried some great troubleshooting steps thus far. I'd be happy to point you in the right direction for further support.
I'd recommend reviewing this article if you haven't already: Why can’t I accept an accountant invitation?
It sounds as though the steps listed in the article are things you've already tried, but it's a good idea to review it just in case.
I'm not aware of any ongoing issues related to accepting an invite from your client, so if you're still experiencing this issue, I'd encourage you to reach out to our tech support team directly so an agent can investigate this further. There may be something on the back-end that's blocking the process.
I hope this helps.
Take care.
