This seems to be caused by aa4mg, which now breaks the bootup until it is properly uninstalled. This is too bad because their android auto solution is better than the e/OS one, since installing google maps literally defeats the whole purpose of using microG and e/OS in the first place.
Edit: Made my own fork of aa4mg that doesn’t install it’s own android auto stuff, but still does the rest of the goodies: GitHub - Maxwell175/aa4mg: Android Auto 4 microG