Do I need to change UUID manually?
No. UUID and other parameters come through the subscription URL.
V2RayTun
V2RayTun does not connect: quick checklist
Most V2RayTun issues are fixed by refreshing the subscription, checking the URL and disabling conflicting VPN or proxy settings.
Common causes
subscription link was not copied completely
profile was not refreshed after parameter changes
another VPN or Private DNS is enabled
the current network filters one of the protocols
What to do
1
Remove the old WersidePN profile and import the subscription URL again.
2
Run subscription refresh in V2RayTun.
3
Check system time, VPN permission and other VPN apps.
4
Try mobile data instead of Wi-Fi.
Common questions
Why did it work after refresh?
The client loaded current SNI, shortId or backup profile that may have changed on the server.