Sobaka1 Trusted credentials or something else? If so, yes, but I turned it back to what it was from default.
Turning off the "Trusted credentials" that GrapheneOS ships with will cause certificate validation failures for unpredictable web sites and services, including GrapheneOS web sites and secure DNS. It's a great way to make the device unstable.
Sobaka1 Time and date set manually
If the date and time are inaccurate, this can cause security handshake failures, so inaccurate date/time is a great way to make the device unstable.
Edit: other ways to make the device unstable include disabling apps that ship with the OS or removing permissions from them. A good way to make the device unusable is to disable the built-in keyboard.