Answer: As you know our TOYDIY 4in1 adopt three layer magnetic bed, after the bed is started to heat up it transfer the heat gradually to the all surface which take a bit time to distribute all the temperature around the three layer. Just observe the first layer is sticking to the bed or not. If the first layer stick well then other layer will be smooth too. The temperature will be increase gradually and reach the actual number.
If your bed is not totally heating as a result the filament is not sticking to the bed then read the other article regarding that issue.