Apple Watch Series 5 battery drain to 10% within 10mins on cellular+gps mode ON

I have my watch charged up full and wear it for a outdoor run using Adidas Running watch apps on Watch mode only (without bringing my phone with me). It’s on cellular network and GPS was turned on while I was running hearing my podcast. Out of sudden after roughly 10mins, my watch alerted me battery reach 10% and shortly, it got reset. After rebooted, my watch is showing left 10% battery life but I can still use it to track my running with cellular network and GPS running for another 20-30mins more before I stopped my exercise. My watch battery life just remained fixed at 10%. Then I left it on the charger to charge it and within less than half an hour, it’s fully charged up again.

I wonder if anyone had this experience before. Is my watch battery something wrong here?