My freezer works albeit leaks below into the fridge compartment through a vent. However the fridge is not cooling

All the big cooling happens inside freezer compartment. Freezer gives little cool air to fridge compartment. Now when the vent blocks that little cold air cannot go into fridge compartment. Thus your freezer works good but not fridge compartment. Milk goes bad but frozen meet keeps good.....

Vent freeze up either due to defrost problemt, defrost drain line problem, Evaporator fan problem or even can be your damper motor not opening due to unit failure or frozen damper door.

Is this is a bottom mount fridge? Hey if your fridge is a fairly a new one. Say less than 8 years old and a fancy one then this is how it works.

a) Fan in freezer circulates air. Mainly to the freezer compartment.

b) Then for the fridge compartment there is a Vent door operated by a vent motor.

Either this vent motor not working and opening, or it is frozen or the thermister that controls the temperature on Fridge compartment is not asking for cooling and thus not sending power to the vent motor to open.

Typically, the fridge gets its cool air via a vent from the freezer. If this vent becomes blocked, then the fridge won't cool. If there is nothing obvious blocking the vent (like a plastic bag) on either side then it is possible the vent is clogged with ice. To fix this, move your food to a cooler and unplug the fridge long enough for the ice to melt (12-24 hours).

I removed the freezer drawers removed back panel inside the freezer,and discovered that ice had built up around the vent which cools the fridge compartment once I melted this using a hair dryer put it back together and the fridge compartment works fine.

If you had an electric fridge the problem is usually the evaporator fan motor ($30).
I suspect that you may have the same problem. Generally, freezers are cooled only, when the fridge needs cooling, the evaporator fan comes on and blows cold air from the freezer to the fridge compartment. The advice below is for an electric fridge but may also work for you, it's worth a try I suppose.
Check to be sure you can get a replacement fan first, they last about 4 - 5 years. Available from a parts supplier or electric motor company.
Unplug fridge, or disconnect gas etc. Fan should be located usually in top of freezer behind a vented cover plate. Remove cover, remove screws holding fan in, may have to cut wires. Replace with new motor, make sure the fan spins the same direction (CW OR CCW) as your old one, if you don't know which way it should spin then be sure it pushes air into the freezer area and doesn't spin backward drawing air from the freezer area.

The freezer get the first crack at cooling and combination units have a fan and adjustable vents to steal some of the cooling capacity for the refrigerator. The vent are normally located in the back of the refrigerator compartment and with these, you can balance the cooling capacity between freezer and fridge. I recommend you swap your thermometer back and forth until you get the balance you want; typically the freezer should be at 5 degrees F or below and the fridge at 35-40 degrees F. Adjusting the control for temperature and having the vents set to supply the cold air you want in each compartment should give you the range you want in each.

clean the coil behind the fridge or under the fridge (where ever they are) and make sure both fans are running, the one in the freezer and the one underneath. If that don't work you may be low on freon change fan motor

Most if not all fridges under $2000 only use a single compressor meaning the refrigeration is provided by venting the freezer air into the compartment. Water under the unit likely indicates the fridge is not properly sealing and moisture is condensing on the cold coils and dripping.

The air flow vents must be blocked. The refrigerator cools from the freezer through those vents, it does not cool independently. They may be clogged in the case with ice. Turn the fridge off and leave doors open for a few hours to let it thaw and it will probably start working.

If you are sure the fan in the freezer is running and you don't feel any air flow out of the top middle vent inside the fridge section, then the damper motor must be bad. The damper motor is behind that vent cover inside the fridge section.