did you add just the coolant? or added water with it?
AISIN coolant is premixed meaning you cannot top up with water at all, you need to make sure every single drop of old water/coolant is removed from system before you add premixed stuff - otherwise if you didnt, then you need to replace the already added coolant with more fresh premix coolant to get it upto the 50% concentration.
meaning - lets say your system holds 4 litres but on drain only 3 litres comes out, you add 3 litre premix (50%) - in effect that is just 1.5 litres of neat coolant.
now your total charge is about 37% - to make this 50% - you need to start the engine to mix everything, then drain this fresh coolant again into a clean bucket.
Then add 1.7 litres fresh 50% concentration coolant and rest from the drained coolant to bring it upto 50%. (the rest of the drained coolant is no good unless you add concentrate to it).
OR
you can just buy 2 litres concentrate, drain and flush, then add the 2 litres concentrate to engine and top up the rest with water. (easy and cheap)