Landscape material shimmering

I migrated my project over from 4.18 to 5.5. My landscape material never had this issue before.

I’m getting this shimmering effect. Can’t tell if it is just an editor view issue. I’ve spent the last two hours playing with everything I could think of in my material, nothing remedies it.

Anyone know what is causing this? I’ve played with MIP settings on the texture, and it doesn’t seem to be the problem.