Drip Tray Overflowing Problem?

Hi, I have a Caravell Commercial Refrigerator and the drip tray keeps overflowing.
I have checked :
the condenser fan seems to be working.
the compressor runs fine.
the pipe isn't blocked or out of the pan.
The fridge seals are correctly sealed.

Everything is running like normal but the pan is overflowing? :rolleyes:

So what could be the problem? I have cleaned the tray out many many times.

Please help