This had been going on for several years. Thought it was due to switching to non-Samsung filters as it was very hit and miss whether I could get the dispenser working well after a filter change. Dispenser worked great if I removed the filter. It finally got bad enough that it was obvious the filter was not the issue.
This turned out to be a pretty easy part replacement. The water filter and tank assembly is held in place by the shelf above and a T shaped tab below. It just slides forward and up after removing the top shelf, disconnecting the electrical connections and disconnecting the hoses. The hoses run directly out the back of the fridge. I used two 1/4" od union connectors to splice the dispenser and ice maker lines on the back of the fridge. Reused the copper fitting on the supply line.
When you disconnect the supply line, you can drain the tank in the old assembly by holding down the water dispenser.
My original part had 3 electrical connections. The new one has two as seen in the pictures. Everything works and part numbers are identical. So I assume it's just a newer design.