It seems to me you are computing the number of climb rounds of every square, you need to do better.

I had the same problem, the way I debugged it (1 hour of work):

• Find the smallest matrix where your program fails
• Output the cost of every square
• Open a google sheet and run the algorithm manually (here's a template for you) : https://docs.google.com/spreadsheets/d/1KTAb_nwolMW05aLZLUrQzUPt2qr1q6bps6-NvRmpIk8/edit?usp=sharing
• See where it fails

but you probably have already solved it now

Wikipedia ftw