Bitmap Displacement Issue

Hello!

I’m sure there’s an easy explanation, but what causes this unwanted effect when using bitmaps for displacements (quick example attached)-- only get it when using bitmaps vs. procedural inputs.

Cheers!

8bit bitmap?

The bitmap must be created in 16 bits. Converting from 8 to 16 won’t solve the problem.
The bitmap must be created at 16 bit initially.

Thank you!! Explains why I only get this once in awhile- thanks for the help