I’ve got you covered, Robinson2.

We can perform some basic browser troubleshooting to improve and speed up your browser's performance. Cookies and caches may prevent you from entering CIS monthly or VAT returns.

Before proceeding, please log in to your QuickBooks Online account using an incognito window to identify if it's a browser issue. Here are the shortcut keys to use:

•  Google Chrome: Ctrl + Shift + N
• Microsoft Edge: Ctrl + Shift + P
• Firefox: Ctrl + Shift + P
• Safari: Command + Shift + N
•  

If this works, go back to your regular browser and clear the cache. This will eliminate old and damaged files and will enhance your system's background processes. If the same thing happens, you can also use another supported browser as an alternative. 

Once you're sign in, please follow these steps to disconnect and reconnect via Advanced settings:

1. Go to the Gear icon, then Account and Settings.
2. Select Advanced.
3. Click Making Tax Digital to expand the section and select Learn how to disconnect.
4. Choose Continue.
5. Hit Disconnect to confirm.
6. Select Continue to return to QuickBooks Online.

Then, you can follow these steps to authorise QuickBooks to connect with HMRC:

1. Click on the Gear icon, then Account and Settings.
2. Go to Advance on the left menu in the Accounts and Settings page, then select the Making Tax Digital header to expand the section.
3. Click on Learn how to connect, then click on Let's go on the Get started with digital tax page.

Once MTD has been enabled in QuickBooks. Follow the steps below:

1. After clicking on Let's go, you'll be directed to HMRC page as shown below. Click Continue to sign in.
2. Enter your HMRC credentials to sign in.
3. Click on Grant authority to continue. The authorisation process will begin.

If the issue persists, I recommend contacting our QuickBooks Online Support. They can pull up your account and submit a ticket for further investigation.

To give you more of an idea about submitting a VAT and CIS return, consider checking these articles which you may find helpful:

• File your VAT return and record tax payments in QuickBooks Online.
• Submit a VAT return to HMRC - MTD for small businesses.
• File a CIS return in QuickBooks Online.

Let me know how this turns out or if you need further assistance with these steps by leaving me a comment. I'll jump right back in to assist you further.