Hi there @Goldie106, welcome to our forum and thanks for your post.
I'm sorry to see that your sons Samsung Galaxy S8 is not connecting to the WIFI. This certainly is a strange one as it is just affecting the one handset. I just want to confirm, have you been able to reboot the hub since trying to connect the handset?
If not, can you please try this to see if this helps with the issue? If you need anything further, I will be happy to help.
Regards
Nathan