Grid shows moiré patterns

Since [one of] the last update[s] my viewport grid shows moiré patterns.

Please have a close look!

Hi - I’m not seeing that on my system here.
Could you please run the Rhino SystemInfo command and post the result here?
Also, do you recall a version where this was not the case?

Yes, of course:

Rhino 6 SR15 2019-3-19 (Public Build, 6.15.19078.12066, Git hash:master @ 9fab17c0d5c0eb2b4cf5a407adb6184caa0bf119)
License type: Beta, build 2019-03-19
License details: Cloud Zoo. In use by: atelier522 (atelier 522)
Expires on: 2019-05-03

Apple Intel 64-bit macOS Version 10.13.6 (Build 17G5019) (Physical RAM: 24Gb)
Mac Model Identifier: iMac18,3
Machine name: 42-ULMA
Language: en

AMD Radeon Pro 580 OpenGL Engine (OpenGL ver:4.1 ATI-1.68.21)

OpenGL Settings
Safe mode: Off
Use accelerated hardware modes: On
Redraw scene when viewports are exposed: On

Anti-alias mode: 4x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: Height

Vendor Name: ATI Technologies Inc.
Render version: 4.1
Shading Language: 4.10
Maximum Texture size: 16384 x 16384
Z-Buffer depth: 24 bits
Maximum Viewport size: 16384 x 16384
Total Video Memory: 8 GB
Graphics: Radeon Pro 580
Displays: iMac (217dpi 2x)

Graphics processors
Radeon Pro 580 (8192 MB)
iMac (2560 x 1440)

USB devices
Broadcom Corp.: Bluetooth USB Host Controller
Apple Inc.: FaceTime HD Camera (Built-in)

Bluetooth devices
Broadcom: Magic Mouse 2
Broadcom: Magic Trackpad 2

Third party kernel extensions

Third party plugins

Rhino plugins
/Applications/ “RhinoCycles” 6.15.19078.12066
/Applications/ “Snapshots” 6.15.19078.1002
/Applications/ “Grasshopper” 6.15.19078.12066
/Applications/ “PanelingTools” 6.15.19078.1002
/Applications/ “Commands” 6.15.19078.12066
/Applications/ “Renderer Development Kit” 6.15.19078.1002
/Applications/ “RDK_EtoUI” 6.15.19078.12066
/Applications/ “Displacement” 6.15.19078.1002
/Users/maasmeier/Library/Application Support/McNeel/Rhinoceros/MacPlugIns/Iris.MacR5.rhp “Iris”
/Applications/ “IronPython” 6.15.19078.12066
/Applications/ “Rhino Render” 6.15.19078.1002

Sorry, but no.
Recently, but I´m not sure how much — approximately it wasn´t in the last one/two versions.

That grid looks very dense so I’m not surprised we are seeing a Moire pattern. What are your grid settings?

I´m really not sure how that (“0.1”) came there …