I was wondering if anyone might know more about this, or it may even be a bug? Appreciate any advice.

Roughly 3 weeks ago, an issue with hard brushes had appeared. They now have aliasing issues that can't be solved with any of the aliasing or smoothing options.

Sometimes it is unnoticeable, other times the strokes have unusual ripples and pixelation.

Examples:

Same brush, some strokes fine, others are not.
Brush at different sizes, showing the artifacts worsen.
Close up a straight line using the line tool.
How things looked in the past, how they look now. (Side by side)

Settings:

Brush Setting
Display Settings

Hey, so, I have no idea if you will see this one, but I figured it out: The "Basic-5 Size" seems to have a precision of 3 by default, probably caused by a bugfix. So, just disable the auto option (f5->brush tips, check the bottom), and set the precision to 5.