It has nothing to do with GrapheneOS, it is not specific to GrapheneOS at all. it was specifically explained to you what is happening.
The AOSP keyboard supports direct boot so that it can be used after a reboot before the first unlock. The keyboard you're using does not. This is why you're locked out. This is also why the disable option is greyed out for the keyboard and the camera, because people keep shooting themselves in the foot by disabling them without understanding the ramifications of doing so.
Another open source keyboard that supports direct boot is Florisboard.
"Freezing" an app, which is unclear what it actually means is different than disabling an app via ADB. You deliberately disabled an app that is not meant to be disabled.
We are happy to help you, but you need to please realize that this is not GrapheneOS' fault, you made a mistake which we can try to help you out with, but let's not make any mistakes about what's happened here.
You should not disable the default keyboard. It's specifically not meant to be disabled, if you want to use another keyboard, you're feel to make that the default, but don't disable the one that comes with the OS. There's a reason why it's there.
WhoTheFuckisAlice Edit: I found an issue in the github... it is a pixel problem since android 13 ... but why the otg Keyboard doesn't work also?
This is not a "problem", is not specific to Pixels, and has nothing to do with Android 13. You're misdiagnosing what's happened. Furthermore, the reason why you're unable to connect a USB peripheral while the phone is locked is because that is the default value of the Settings > Security > USB accessories setting.