Flashing red light when charging after battery replacing

Hello guys,
Today I received a new battery for my friend's JBL Flip 1, it is equivalent to the original from what I've seen and checked if the wires are in the good color order (from left to right : black, red, blue/yellow). The voltage & capacity is the same (7.4V, 1100MAh).

I think that it's not charging, it's flashing a red light when plugged in with OG charger and seemingly not charging? I'm not sure about that.

Is that red flashing normal or a problem? Thanks in advance.