Cockpit freezer performance

I have the Novakool WF1900 cockpit freezer on my C30S. I'm not happy with the performance: Best case, the temperature gets down to -8C, often only -3. It takes a long time to freeze items which I put in (like prawns). Nothing seems wrong but that just not a good freezer performance. Anyone has seen similar issues?

I have an old Novakool R4500 in my C26 - fridge mfg date reads 2007. Very reliably cycles -10C/-15C even under extreme summer-oven cabin conditions. Amazing.
/diatom

Update: It looks like the described performance is normal. Here is the information I got from the Novakool support:

"The freezer was designed to be around -6 to -9C.

That is the way the unit was designed.



Be advised to not compare the fridge to a household fridge or freezer. This was designed to be a holding unit.



The temperature inside the fridge or freezer depends on variables like the ambient temp, thermostat setting, how many times the doors are opened, what items are stored inside the fridge/freezer, etc.



It is just doing its best to keep
the unit cool."