Inconsistency in CI testing for noarch CRAN package

Issue: I have been trying to push my R package gprofiler2 to conda-forge and I'm seeing an unexpected behaviour in CI tests. Without actually changing anything in the meta.yaml file, checks fail in different platforms in separate commits. In one push, osx and linux fail, in other windows fails, and all other combinations as well. There seems to be something random happening. Do you have any idea what is going on?

The error message is always "conda.exceptions.UnsatisfiableError: The following specifications were found to be incompatible with each other:"

https://github.com/conda-forge/staged-recipes/pull/9530