I have the same phone and had the same issue last week out of the blue, I updated Android Auto from version 8.0.1232 beta to version 8.1.1234 beta and the problem seems to have gone away. I think a lot of issues stem from AA version and not necessarily the Carsifi phone or device version.
There was an update a couple months ago that made a night and day difference to the way AA runs on my S21, which was very laggy beforehand.