That's not good @Liamp972
Try a different charging cord and charging plug if you can.
If you perform a forum search and or Google search you'll find various generic troubleshooting tips to try.
As a last resort back up and factory reset.
A Samsung Experience Store / Samsung Service Centre can take a look at the phone for you.
Daily Driver > Samsung Galaxy s²⁵ Ultra 512Gb ~ Titanium Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help. " This is the way. "
