magento 2 event sales_quote_address_collect_totals_after is changing paid amount

I am adding some custom value in my tax amount after select country by using sales_quote_address_collect_totals_after even, everything is working fine but after complete the online payment my paid amount increase by this custom tax value means grand total and paid amount is different, paid amount is more than grand total, even at the time of payment gateway show correct grand total value but after payment paid amount increase by custom tax value.

Below is the code that I am using to increasing tax value

 $total->addTotalAmount('tax', $this->additionalTaxAmt);

Seems event is calling after complete the payment and increasing paid amount.
Anyone have idea how to solve this?