ztests | Easy integrations tests with containers | Continuous Deployment library

Note that the expected result and the setup are slightly ambiguous, so there might be several ways to go.

Simply put: Material with shader A (Unlit) is covered up by B (Transparent) because B is drawn after it. "Queue"="Transparent" is the flag responsible for that effect in B. Shader A doesn't have it so it uses the default "Geometry" queue. (You can read about the index value used under the hood here: https://docs.unity3d.com/Manual/SL-SubShaderTags.html). So in this regard you could specify the queue indices explicitly, and make sure they match your expected behavior.

This disregards another aspect: the ZBuffer, which deals with occlusion of one mesh by another, made so that they are actually not dependent on that draw order. Pixels can be discarded based on a depth test, and depth can be written by object if specified to do so. (https://docs.unity3d.com/Manual/SL-CullAndDepth.html)

Meshes display z-fighting if both of them write and test, and are co-planar (in the same spot) or the buffer has low precision so the values stored make it seems like they are.

Provided that both your meshes need to be occluded and occlude others and themselves, one way would be to set B (Transparent) to use ZTest Less, so that it only appears when A is not present at all, even if drawn after A, and even if co-planar with A.