Naming Series in sales Invoice ERROR

I changed the naming series of Sales Invoice to GST-.###.-1920 through Naming Series tool. When I created the first Invoice the series came to be GST-001-1920 which was perfect, but due to some issue I deleted the Invoice, later on when I created another Invoice the series jumped to GST-002-1920. I tried resetting the naming series by update series tool selecting the prefix and setting the current value at 001, however as soon as I click update and create a new invoice the series goes +1 , If I click update button in the “update series” twice then the new Invoice will be with number jumping to +2.

I tried reloading and clearing cache nothing seems to work, I have made and deleted many Invoices now the series has reached to GST-102-1920