AirPod Pro Charging Issue

Problem suddenly appeared charging my AirPod Pro unit ... yesterday it said the AirPods were charged at 6% and the case at 1%, despite being plugged in they wouldn't charge. I used the same USB cable to charge my iPhone and it worked so I know it wasn't a bad cable or bad power source. Then all of a sudden it said the AirPods were charged at 33% and the case at 8%. 10 minutes later I was down to 3% and 6%. It's crazy. I reset the AirPods by pushing the button on the case, still wouldn't charge all last night. Then all of a sudden this morning it IS charge. Now the AirPods are 99% and the case is 65%. What the heck is going on? Anyone else have this issue? Is the charge information transmitted to my iPhone incorrect or is it really not charging or what? It's very weird.