Individual Blueprint drop rates are so weird

Played a day raid in Stella today and literally pulled 5 blueprints. Two in the same trash can. It was insane. And this is after getting one in the last two days.

That being said, my gripe is this. I have maybe 50 hours topside. I don’t know right now. Unlocked maybe 25 blueprints total. And I swear I have gotten jolt mine to drop at least 20 times. There a few others I’ve gotten multiple times but I got two jolt mines within three minutes of each other today.

What gives? Anyone have a real explanation?