Had a funny thing when my keyfob were low on battery.
It allowed me to unlock and start the car but refused to lock it. (Second key worked fine)
Replaced keyfob battery and everything worked fine.
Only symptom of low fob batteries on mine was the keyless entry became a bit unreliable, this was with both fobs. Change the batteries in both and all ok.
Note to self.
When following instructions make sure you remove little sticker from back of battery having replaced both keys or the car won’t open causing mass hysteria and panic!