IPv6 broken when IPv6 leak protection is disabled

[santost12]

ProtonVPN app version: 1.16.1
OS Name: Windows 10 Enterprise LTSC
OS Version: 0.0.17763 N/A Build 17763

After disabling the IPv6 leak protection and enabling the VPN, IPv6 stops working. I am able to ping my IPv6 default gateway and my own IPv6 address but I can't ping Google's IPv6 address. I'm using ipv6.google.com for the test. Before enabling the VPN, I am able to ping that address. I tried removing the IPv6 default gateway route and manually adding it. I'm receiving "General failure." when I try to ping it.

Please look at this video for more info: https://www.youtube.com/watch?v=rOmb8wUi2ks