V17 hanging a lot and it's not stable, all my issues fix after return to V16

i have 3 Device XG 125 and yesterday morning i have updated 3 devices to V17 and after 3 hours, a lot of issues happened like the following :

1- VPN site to site not connection, from the log it say failed ( no more details in log )

2- suddenly when i try to logon to sophos main page , after enter the username and password, it will not login, even no message password is wrong or any message, it just stuck ( fix by hard restart, then it appear 2 time more then fix by hard restart)

3- it's not responding to SSH, mean i enter username and password and i choose to restart or shutdown but, nothing happened 

4- after restarting then login to firmware page to check the current version, it will stuck and nothing appear

all of this issues appear in all of my XG ( 3 devices in 3 different location ), and all working back normally after back again to firmware 16, so is 17 tested or not ? i'm always doing update for the new firmware and no issue at all, this the 1st time, and this effect my organization for 2 hours, 

and can any one advice me the following :

1- is there any support hotline of sophos in UAE?

2- what is benefit of having Enhanced Support, and what different between it and Enhanced plus Support ?

3- what is the backup solution you can advice if one device (hardware or software failed ) ?