but I was just wondering if it's supposed to be happening here or if there's a fix.
I don't think it is "supposed to be happening", it just does happen.
Furthermore, effects like the diffraction spikes disappear when you go beyond a certain res. Again, I'm unsure if this is just me experiencing this. The problem seems to affect all the recent builds I've tried.
I mentioned this to SpaceEngineer a while back. What the engine really needs is proper scaling for these effects.
The only solution is to turn those effects up to be larger so when you do take high resolution screens they get scaled down to what they should be. Doing this can be quite tricky however.