From what I have seen, the numbers aren't really random at all. they run in streaks and if you keep working the same place for a long time, it eventually evens out. It's just super noticeable when you miss several times in a row, and then later you'll hit the same about of HQs in a row and it balances things out.

A lot of it is confirmation bias, but there is definitely something odd with the RNG system.