Compare data in one workbook across two sheets

Every month I make a stock compare of what is in our system and what the cold store tells us is in their system. Because the combination of material and batch number is unique, I use CONCATENATE as a criterium for SUMIFS to calculate what the cold store has in their system and compare that value to what is in our system. So far, so good.

What I am missing, is the materials that is in our system but not in the cold store, and vices versa. I can use the side by side view to compare data and find the differences but this takes quite some time. Is it possible to use a formula to look those materials up? And perhaps copy them to at least the tab cold store? Or another suggestion to solve this?

In the attachment a sample. On tab cold store and on tab SAP I have highlighted a material that does not occur in the other sheet.

Thanks in advance for your help, have a nice weekend and be safe!