Trouble downloading Catalina 10.15.7 to MacBook Air in UK

Hi. I arrived in the UK from the US three days ago and need to do the Catalina 10.15.7 update to my MacBook Air. Yesterday, it said it would take "four days" to complete so I stopped it. Today, it won't work download at all. I am using a VPN set to a US server. Unsure if this is related to my location / are iOS updates different if the user is not in the US? Thanks for any insights