There is a bug in the sales tax report query logic. I've tracked it down with a solution for you.
The tax summary is correct. Reads the sum of the tax lines amount. In the sales tax report the from tables in the query of payments and tax line are matched on the receipt. There is only one tax line per receipt. But there can be several payments.
Suppose 10% tax rate.
Ticket 1 is $100 plus tax. For a total of 110. Customer pays $60 credit card, $50 cash.
Query will match $60 payment with $10 and $50 payment with same $10 tax line reporting $20 sales tax collected in error.
Grouping by tax line Id won't work. I ended up grouping receipts in the payment table and selecting the max tax amount. This only works for me as I have 1 tax or 0. With multiple tax rates not sure if it works. Good luck