Water leak from the Furnace

Water leaks right after the HVAC condenser switches off. I inspected the drain pan, no signs of cracks. cleaned evaporator coils, changed the filter and cleaned the drain. It lasted about three weeks without leaking and now it started to leak again right after condenser turned off. What can I do next?

Thanks in advance

source https://hvac-talk.com/vbb/showthread.php?2222227-Water-leak-from-the-Furnace&goto=newpost