I am using QuickBooks 2020 and haven't been asked to sign in, in 2 months.

This is what I did:

Run> shell:startup
Run> shell:common startup
Remove anything that refers to QuickBooks in these folders. (in my case):
Intuit Data Protect
QuickBooks Update Agent
QuickBooks_Standard_21

Run> Services.msc and Disable:
Intuit QuickBooks FCS
QBCFMonitorService
QBIDPService

Lastly go to:
Local Disk (c:)> Program Files(86)> Common Files> Intuit> QuickBooks> QBUpdate: and renamed the QBUpdate.exe file qbupdateold.exe

So far so good