Hi there, Bookmark has no connection to payment transactions.  This is an issue you need to bring to Moneris as they are do the payments with no back and forth connection to Bookmark what so ever.  

Same thing kept happening to us as of January of this year, it is Moneris, or more specificly "Kount" which is another company moneris uses now that is basicly an AI anti fraud tool. Moneris isn't much help since Kount is its own entity, they just tell you the program is doing what it's supposed to, but many of our repeat customers are now unable to use our site. Not sure if Kount recently changed their code or what, but it is blocking like 80% of our sales. We had to add an e-transfer payment method to get around this. Hope this helps you!