Help with first flashlight - strobes while charging?

Hey everyone. I recently found the flashlight community on Reddit and got super interested in trying out a cool flashlight. I have a nice dark forest in my backyard so I thought I’d get a flooder first. After some research I settled on the Astrolux S43s. It finally got here today but when I try to charge it with the built in micro USB it just strobes and the UI button flashes. I plugged it into a charge doctor and it reads 5.3v and 0.02A so it seems like it might not be getting a charge. If I open it and remove the battery while still plugged in, nothing changes. So either the included cell (Samsung 18650) is fried or the built in charger is.

Which sounds more realistic? Am I being an idiot and missing something obvious?