The moment I launch tixati, or if it's launched before, my VPN SurfShark stops working. Used to work before with no problems.
It's probably some Windows 10 updates that broke it (since I didn't update any of the two software for a while)
I updated both tixati and VPN: no results.
Any ideas why tixati breaks a VPN connection?

I would first suspect Surfshark to silently cancel the connection when it detects Tixati. Try with a more reputable VPN provider.
By the way what does "breaks" mean? Is it still connected in the app client and Windows connections but no more traffic? Does it disconnect?

I would suggest Surfshark stopping connection due to Split Tunneling configuration.  Double check Surf shark's settings and maybe uninstall and re-install it.  I personally have no experience with Surf Shark I'm stuck with PIA for now because I signed up for 3 years and don't want to spend the money again. I'm guessing it's the cheapest but I was looking into another one which would shut down Tixati if it stopped VPN software disconnected.

Hey Crazyd,

You said " I was looking into another one which would shut down Tixati if it stopped VPN software disconnected. "

You know you can associate Tixati with the PIA network adapter in Tixati's network settings: connections>local IPv4/6 address or interface.   Do that and Tixati will not send or receive anything unless the VPN is active.