If the pane were very cold, that would be the explanation for the condensation (according to the dew point table). It could turn out that despite heating and ventilation, no improvement can be achieved. If room temperature and humidity are constantly within the normal range, no water should form there. If it does, the component is probably defective. If the pane has a normal temperature for such a window, it is more likely due to heating/ventilation. The question then is, what is normal as the indoor temperature for window panes. However, I would claim that 12-13° C is not normal. According to the dew point table, that would be the temperature the panes would have to have for dew to occur at 21° temperature inside and 60% humidity. Or in short: if both humidity and room temperature remain within an appropriate range for living spaces and do not leave it, then no mold and no condensation may occur. As a tenant, one is certainly not forced to keep the humidity below 40% or constantly heat to 25° because of leaky windows or cracked facades just to prevent mold.