M247 proxy ammo M822 not working

I’ve been using the M247 with M822 proxy ammo over the past few weeks and have noticed it’s having issues destroying aircraft. I play ground arcade so aircraft usually come straight towards me. It’s bizarre that even when I’m shooting at a plane coming directly torwards me it often fails to stop the aircraft. Before this what i assume to be a bug, i had no issues downing aircraft. Every game that I’ve played with it has had this issue to the point i don’t even have it in my lineup anymore.

The radar lead indicator isnt very accurate, lead slightly ahead of where its telling you to shoot.

I’m not talking about just the radar lead indicator. When planes are coming exactly at me and i aim at the plane it just magically gets through my fire. In a straight line that plane shouldn’t survive a full burst of 40mm Proxy ammo. In this scenario a plane is flying directly at my M247 in a straight line and will hit the ground