Compare 2 sheets, Highlight 2 new column entries

Every week I pull a report showing out of stocks. It shows a unique number for each customer 'Customer' in Column H. It shows a unique number for each product 'ASW#' in Column L. There are many common columns. What I am trying to highlight for myself is when a new customer with a new product shows up on the latest week's report showing me that as of this week that customer did out of stock on the particular product.

I pull this report weekly but it can only be pulled on the month's numbers, so in this case March 2020. I have been manually comparing. When I get to the end of a month there will be repeats of customers as it will include customers that would have been out of stock the week prior too. I start missing line items.

I've attached a sample of the Excel spreadsheet. If there is a good formula I can use, great! If I need to create some other reference columns or data just let me know. The real spreadsheet has a tab for each week of the month.

In other spreadsheets where I compare inventory levels only, I have a 'Latest' Spreadsheet tab, 'Previous' Spreadsheet tab and then the 'Compare' tab and use VLOOKUP, BUT this just compares one thing. What I don't know how to do is identify the customer AND the ASW# as new for the week.