So.... here's the deal.Source: https://clips.twitch.tv/GenerousRelentlessDonutBibleThump
Here is video proof of the poopoo I have to deal with when I try this, notice how many missiles I go through before the game FINALLY says I have the angle, why it can't just tell me this in bips, beeps or colors BEFORE I fire the missile is beyond me, guess were so far into the future that everyone should be just a mind/asteroid reader.
I was able to recreate what's in your video... but.
- it took me about a few dozen attempts, and
- it had absolutely nothing to do with "pixel perfect angles" or anything like that.
- it was very sporadic
I retried on all sorts of angles onto the vein and had no problems at all.
Imo it's definitely a bug... but i couldn't guess what. There's a bug i know of where selections in the nav panel simply don't stick... you ask to lock a planet or system and it just doesn't, could be related or not. But what you're experiencing is definitely not part of the design, and a only came up recently because I've mined plenty since the last update and never had this happen before.