I too have this problem; I am also a Vodafone Gigacube user...
Did Squarespace support ever solve the issue for you, @straight8?
I have the same problem... seems to be standard issue for us on voda 4g. The only work around which i found which works for me is to activate a VPN before logging on to update or add pictures to my website. It was fine using the VPN even though i am still on 4g because squarespace thinks its a standard internet connection there is no issue. Sorry i could not be of more help but i hope this works for you.
Squarespace page update problems: 502 error
in Customize with code
Posted
I have the same problem... seems to be standard issue for us on voda 4g. The only work around which i found which works for me is to activate a VPN before logging on to update or add pictures to my website. It was fine using the VPN even though i am still on 4g because squarespace thinks its a standard internet connection there is no issue. Sorry i could not be of more help but i hope this works for you.