The housing lottery was not fair due to bugged random function

[Somnolence]

There's a chance that's the case, but the number of players who lost their plot to number 0 is a little TOO high for the chances of it to be a simple coding issue.

Most likely, what actually happened is that the system ended up being overloaded with the number of processes it had to run for calculating the winners, and crashed midway. There is usually a failsafe to prevent the whole system from crashing altogether. While it can't output a null value, it most likely defaulted to 0. This meant while some winners were processed, other plots just outputted a winner being 0.

Your theory seems to be false, as 50% of single bidders seem to have lost to 0, while this is far less common for housing wards which had many participant, so the random function was indeed bugged.