Have you tried clearing the cache and data of the galaxy store then reseting app preferences > Go to Settings > Apps > tap on the three dots in the upper right corner then select "Reset app preferences". This will not delete any data but will reset all app preferences, which might help restore functionality.
ALSO:
Clear the cache partition - Turn the phone off (shut down) - Press and hold the Volume Up key, then press and hold the side key. - When the Android system recovery menu options show release buttons. - Press the volume down key several times to highlight wipe cache partition. - Press the side key to select. - Press the volume down key to highlight yes, then press the side key to select. - When the wipe cache partition is complete, Reboot system is now highlighted. - Press the side key to restart the device.
You could also utilize the "repair apps" option in the recovery menu by following the above steps but instead choose "repair apps".
