I am wondering if the lack of actual Emer mask training with sim providers in pressurized airplanes due to Covid the last few years is creating a situation where more of these accidents are starting to occur. I like to check not only if there is O2 flow in Emer mask but also to see the quick donning straps inflate properly. I have seen where the mask has O2 flow but the inflatable straps on a quick donning type won’t properly inflate.