Reproduced and Confirmed - Spacemarine1.9.5, auto crew quarter fill less than enough crew quarters with very short deployment times
The function number - n/a
The complete error text - n/a
The window affected - class design window
What you were doing at the time - testing
Conventional or TN start - TN
Random or Real Stars - real
Is your decimal separator a comma? - No
Is the bug is easy to reproduce, intermittent or a one-off? - easily reproducible
If this is a long campaign - say 75 years or longer - n/a
when building a ship, the automatically added crew quarters can be too small in size when the deployment time is very short (start to show this behavior when <1 months)

The above can be reproduced by creating a new class design, remove all default components, and add 8 ECCM-1 components, then set deployment time to 0.01 months.