Yeah around the piston, presume it’s cracked or chipped or whatever. Haven’t really investigated.
Rode the bike, it was all working fine, put it away. Pulled it out 3 days later and front brake was screaming and not biting. Back of pad had a bit of fluid on it.
That sounds a bit like it. If the pistons don't fully retract even when pushing it's a warranty case. Shimano warrantied my calipers after a bit of paperwork, but that's Aussie so might be more or less tricky where you are.
But where? At the pistons? Cracked piston maybe if it's the ceramic ones?