Wireless Slow Charging with MagSafe Devices

Hi all,

Just recently while on holidays my iPhone 12 has stopped fast charging with my MagSafe charger. I also have a fast charging wireless battery pack which it does not fast charge with either. It used to fast charge on both.

I have searched endlessly to find this problem and so far I have Forced Reset it, reset Network Settings, deleted apps.

Can someone please help or give me something that could fix it?