Hi @vitojdelre
Looking at the parts list for Frigidaire models FPHC2398LF1-LF4 (can't find one for -LF5 model they all have what is known as a Dispenser Heater Kit (p/n [https://www.ebay.com/itm/254680490181|5303918596]) (example only to show image of part where you can see a small heater element)
Looking at the schematic diagram (right side of p.2 in the [document|41022|service data sheet] (same one for all 4 models so presume it will be the same one for your model) it shows a ''valve heater?'' connected to ptd main board connector J4 / 1 & 3 terminals and also a ''dispenser housing heater'' connected to the dispenser control board J3/4 but that seems to be more associated with cubed/crushed ice dispensing than water.
It may be worthwhile to disconnect the power to the refrigerator and unplug the J4 connector wiring harness plug from the ptd main control board and then test the wiring between J4 1&3 ''on the plug'' for continuity through the heater element,, just to check if it is OK or not.