I'm seeing this on a few laptops with SSD's. The behaviour is that if the device isn't interacted with in any way, the machines hang for 2-4 mins at boot.
Seems to be related to the fix for CVE-2018-1108 - random: fix crng_ready() test https://security-tracker.debian.org/tracker/CVE-2018-1108 Pedro & Sten, can you try introducing entropy into the systems affected when they appear to hang, to see if this reduces the delays? eg: moving the mouse, tapping shift/ctrl/alt keys, pinging the device on the network if network is already up, etc? I suspect this bug can be merged with 897599, 897632 and 897917. -- Stuart Young (aka Cefiar)