Hello there, MattGil.
Thanks for reaching out to the Community about your concern. Let’s perform some basic troubleshooting steps so you can successfully send the CIS return.
Web-based applications like QBO collects cache files to save time when loading information and images. When there’s too much data it may lead to unusual behaviors in the online program.
To begin, open your company using a private window or incognito mode. This type of session blocks websites from storing data and is a good place to start to see if the issuer is caused by the cache.
If you’re able to submit the CIS return seamlessly, clear out the cache on the regular browser. The process helps improve the overall browsing experience.
However, if the issue persists, I suggest manually file the return. You can print the one in the company and enter the information in the HMRC website.
If you encounter any errors, I appreciate any details you can share. This is to determine if we have an open investigation.
I'm also adding some guides that provide an overview of how the online program handles the CIS.
Don’t hesitate to let me know if you still need help with QBO. I’ll be glad to assist further. Have a good one.