I have the same problem.  My sales tax reports were just fine until sometime in 2021 and ever since then the report show zero (no matter how much sales tax is noted on the invoices) and i'm having to do it manually.  UGH!  There probably was a programming change and it messed up the reporting.  I use the % in the sales tax section on the invoices so that isn't the issue.  PLEASE HELP, this is wasting my time.