There is a problem found with Raspberry Pi 4 Model B Rev 1.1 which causing RPi4 stuck at booting.
And the workaround is to add a line in config.txt file under boot partition(FAT, ~105MB):
enable_uart=1
This method only needed for flashing a brand new 3.8.5 image, also the problem is reporting to the engineering team, the fix will be included in the next 3.8.6 release.