You've come to the right place to get help with your 940 form concern, @info1428.
As long as your 940 forms were archived, you can access them in QuickBooks Online. Just make sure to select the correct filter to locate them right away. Please see the screenshot below as your guide:
If you don't see them, you can try performing the said task using a private browser. QuickBooks Online (QBO) uses cache to load and access pages more quickly. However, too much of them can cause unusual QBO responses.
An incognito session doesn't save the files and history of the pages you visit. Hence, a good place to isolate unexpected QBO behavior. Here are the shortcut keys you can use to access one:
Ctrl+ Shift + N for Google Chrome .
Ctrl + Shift + P for Mozilla Firefox and Microsoft Edge .