lovefromisrael which keyboard? I don't know if the default keyboard supports Hebrew.
If you've removed the keyboard's network permission, like with GBoard, the app may need to download a language pack or something. I'd clear the app's storage, grant the network permission, then set it up again, type some Hebrew, and when everything seems to be okay, remove the network permission. I've had to do this with GBoard a few times before.
If you're using a different keyboard, I'd still start with clearing the app's storage to see if that fixes the problem.