I have a Deco network inside. I also put a deco X50 outdoor but the signal outside is still weak. It is used to manage portal, camera, pool switches (Alexa controlled) which are 20-30m far from the X50 (no need to have high data volume but a sustainable connexion). 
 

Which device outdoor should I install to have a better signal ?

Ideally I would like to extend the WiFi from Deco not to have to put a network RJ45 cable. Only AC is available outside otherwise I will hate to drill the stone wall. 
 

Thanks for your support.