Frigidaire refrigerator not getting cold. The freezer unit very cold and ice maker makes ice. There refrigerator part does not get cold. What can I do?

There is only one cooling unit in a refrigerator/freezer unit and that is the freezer.

In other words the freezer part gets cold and cool air is circulated to the refrigerator part. Check to see that the vents are not blocked and that the circulation fan is running. Also check that the refrigerator door is closing and sealing properly.

It is possible, but not too likely, that your defrost system is either failing or has failed. You also should pull it out from the wall and unplug it and remove the back in order to check the coils and the condenser fan to see if the coils are dirty and the fan works because many times I get refrigerators that will freeze but with dirty coils will not cool the refrigerator very well, and even if the failure to cool the refrigerator is due to the fan not working in the freezer, you still need to clean the condenser coils and fan blades or the next failure will be the compressor. If you need it, I can send the manuals to this unit if I know what kind it is (side-by-side or regular).

Also check your refrigerator door magnet to make sure its sealing and has no big gaps. If the door seal comes off or is badly damaged (particularly at the bottom) all the cold air can fall out (cold air sinks and hot air rises).