Looks like the processor on the U/I is bad….I would replace the user interface to correct your issue. See video link below for a videos on your model. https://www.appliancevideo.com/appliances/samsung-rf263teaesr-refrigerator/

Self Diagnosis: Press both buttons (Energy
Saver– Alarm) simultaneously (No sound
when both buttons are pressed at the same
time) ‟til the display quits blinking and
beeps, 8-12 seconds, then release and read
Fault Codes.
This will also cancel the Fault Mode created
Error Items LED TROUBLE TESTING
I/M-SENSOR (R on Tw in
I/M units)
Ice Maker Sensor Error- open or short-circuit, connector failure. Cause is
also a temperature reading > 122°or < -58 ° F
The voltage at MAIN PCB Sensor
betw een 4.5V~1.0V
R-SENSOR
Refrigerator Room Sensor Error- open or short-circuit, connector failure.
Cause is also a temperature reading > 122°or < -58 ° F.
The voltage at MAIN PCB Sensor
betw een 4.5V~1.0V
DEFROST SENSOR OF R
ROOM
Ref. Defrost Sensor Error- open or short-circuit, connector failure. Cause is
also a temperature reading > 122°or < -58 ° F
The voltage at MAIN PCB Sensor
betw een 4.5V~1.0V
R-FAN ERROR This error indicates the Refrigerator Evap Fan is not spinning at the correct
RPM or the fan feedback line is open.
Fan voltage at MAIN PCB shall be
betw een 7V~12V
I/M FUNCTION ERROR(R
on Tw in I/M)
This error indicates the Ice tray has not returned to level after an ice harvest.
The error is displayed after three failed attempts. Replace I/M
COOL SELECT ZONE
SENSOR
Cool Select Zone Sensor Error- open or short-circuit, connector failure.
Cause is also a temperature reading > 122°or < -58 ° F
The voltage at MAIN PCB Sensor
betw een 4.5V~1.0V
R-DEFROSTING ERROR Refrigerator Room defrost heater- open or short-circuit, connector failure, or
defective temperature fuse/bi-metal. Defrost on over 80 minutes
Disconnect defrost connector
from PCB, check resistance
PANTRY-DAMPERHEATER
ERROR
Sensor system in Pantry Room errors Disconnect heater connector
from PCB, check resistance
PANTRY-SENSOR ERROR CR Room Sensor Error- This can be an open or short-circuit, contact failure.
Cause is also a temperature reading > 122°or < -58 ° F.
The voltage of MAIN PCB Sensor
betw een 4.5V~1.0V
I/M-SENSOR (F on Tw in
I/M units)
Ice Maker Sensor Error- open or short-circuit, connector failure. Cause is
also a temperature reading > 122°or < -58 ° F
The voltage at MAIN PCB Sensor
betw een 4.5V~1.0V
I/M FUNCTION ERROR(F
on Tw in I/M)
This error indicates the Ice tray has not returned to level after an ice harvest.
The error is displayed after three failed attempts.
Replace I/M
WATER HEATER ERROR Error is displayed w hen the w ater reservoir tank heater is open or shorted
Disconnect heater connector
from PCB, check resistance
EXT-SENSOR Ambient Temp. Sensor Error- open or short-circuit, connector failure. Cause
is also a temperature reading > 122°or < -58 ° F
The voltage at MAIN PCB Sensor
betw een 4.5V~1.0V
F-SENSOR
Freezer Compartment Sensor Error- open or short-circuit, connector failure.
Cause is also a temperature reading > 122°or < -58 ° F
The voltage at MAIN PCB Sensor
betw een 4.5V~1.0V
F-DEF-SENSOR Freezer Room Defrost Sensor Error- open or short-circuit, connector failure.
Cause is also a temperature reading > 122°or < -58 ° F
The voltage at MAIN PCB Sensor
betw een 4.5V~1.0V
F-FAN ERROR
This error indicates the Freezer Evap. Fan is not spinning at the correct RPM
or the fan feedback line is open.
Fan voltage at MAIN PCB shall be
betw een 7V~12V
C-FAN ERROR This error indicates the Condenser Fan is not spinning at the correct RPM or
the fan feedback line is open.
Fan voltage at MAIN PCB shall be
betw een 7V~12V
FRENCH DOOR ICE ROOM
SENSOR
Ice Room Sensor Error- open or short-circuit, connector failure. Cause is also
a temperature reading > 122°or < -58 ° F
The voltage at MAIN PCB Sensor
betw een 4.5V~1.0V
F-DEFROSTING ERROR
Freezer defrosting heater- open or short-circuit, connector failure, or
defective temperature fuse/bi-metal. Defrost on for over 80 minutes
Disconnect defrost connector
from PCB, check resistance
FRENCH DOOR ICE ROOM
FAN ERROR
This error indicates the Ice Room Compartment Evap. Fan is not spinning at
the correct RPM or the fan feedback line is open.
Fan voltage at MAIN PCB shall be
betw een 7V~12V
ICE PIPE HEATER ERROR Error is displayed w hen the ice maker fill pipe heater is open or shorted. Replace Fill Tube Ass’y
Uart ERROR
COMMUNICATION
This error is not applicable, if the error is detected during diagnostic testing
please ignore it.
No Repair Necessary
L↔M ERROR
COMMUNICATION
Communication error w ithin the Main PCB Replace main PCB
P↔M ERROR
COMMUNICATION Communication betw een the Main PCB and Keypad
Check w iring in door & cabinet,
Panel PCB, Main PCB
Samsung ‘Refrigerator’ Diagnostic Code Quick Guide

tsRF268AB