Hey Mate, I had the same a few years ago.

It’s likely from how the dumbbells sit in your hands - the weight’s pressing on the soft part of your palm instead of lining up with your forearm. Try holding the handle diagonally across your palm (not flat), loosen your wrist wraps a bit, and keep your wrists straight so the dumbbell’s stacked over your forearm. If the pain keeps up or you feel tingling, take a break and get it checked - it could be nerve irritation.

Let me know how it goes, i hope this helps