On my end the game sometimes freezes when changing AA or scaling mode, then returns to normal after 10-15 seconds. Does it just stay frozen for you?
Sorry about the late reply, from what I can tell by looking through posted issues on Godots github, they forgot to add some of the new shader compilation stuff to when graphic settings are changed. Hopefully they can fix it in the next engine update.
And just out of curiosity, have you had any issues with the vulkan build? And what are your computer specs? Gpu, windows version and so on.