It's exciting to learn you've accepted a new client invite! It sounds like your business is growing. It's important you're able to view you new client and I'll be happy to point you in the right direction so you can enjoy the amazing features offered in QuickBooks.
Based on the details you've provided, I encourage you to check out to accept the invite again a while using a private browser window. In case you're still not seeing your client, I encourage you to contact our phone support team sot they can take a closer look into this. Here are our contact details:
Schedule a Callback or start a Chat: click (?)Help in the upper right in QuickBooks Online > type and enter "Contact support" into the QB Assistant > click Contact Us > explain your situation > click Let's Talk > choose Get a callback or Start a Chat.