A bigger software issue these days is 'supposed' redundancy that actually isn't. Like the Boeing 787 that has 4 generators fail at the same time, because their software has a flaw.
Let's put this "flaw" in perspective.
1. It has NEVER happened operationally, only in the test lab.
2. It will ONLY happen if the system runs
continuously for 248 days.
3. The "workaround" to prevent this from happening is to shut down the system before 248 days have elapsed.
4. No one anywhere has ever or will ever run a 787 continuously for 248 days. Conclusion: not a problem in any meaningful sense, but Boeing still notified its users of this "flaw", which was eliminated in the next software revision.