Hi @patrick43472
Check if the [https://www.searspartsdirect.com/model/4caxepvkgy-001482/samsung-rf20hfenbbc-aa-00-bottom-mount-refrigerator-parts|drain tube] (part #12 cabinet diagram) located in the drip tray below the evaporator unit which is behind a panel at the back of the refrigerator compartment is not blocked. (Access to the evaporator unit etc is through the door at the front by removing the panel at the back of the compartment).
This tube leads to an evaporator pan (part #14-2 cabinet diagram) located underneath the compartments.
When the refrigerator is in its defrost cycle, the meltwater from the defrosting accumulated ice build up on the evaporator unit, drips into a tray below the evaporator and then drains down to the evaporator pan and is evaporated naturally.
If it is blocked then the meltwater will back up and overflow into the refrigerator compartment.
There is also a similar drain tube below the evaporator unit inside the freezer compartment that does the same thing.
Try pouring a measured cup of water down the drain tube and check if all of it reaches the pan below the compartments.
''***Be safety aware*** disconnect the power to the refrigerator first''