When I attempt to set the due date between a random interval of 0-7 it keeps randomizing the graduating interval of that card; some would be 2d others would be 2-3months. I tried this on my wifes account and the same problem persists. This was working find just a few days ago. Unsure what to do as i need to do my cards.
It sounds like you’re using the default (SM-2) scheduling algorithm – so the length of the current interval matters a lot in determining the next interval – What spaced repetition algorithm does Anki use? - Anki FAQs.
If you’re only changing the date, but not the interval, that could account for the difference you’re seeing.
I doubt it’s randomizing. But to talk about what’s happening with any specific card, we’d need to see your deck options, the Card Info for that card, and the values on the answer buttons that are concerning to you.