MAM policy targeting unmanaged devices is affecting managed ios device

Thanks, that looks like it may have been the issue. I did see mention of that setting in the documentation, but wasn't clear on how to set it. I assumed since I was using the templated configuration builder for outlook, that it would have included all the necessary settings. Thanks to your post though, I found this blog post which explained the setting a bit more clearly to me. Though, I see now looking at the docs again it also mentions an IntuneMAMDeviceID setting, while the blog post made no mention of that. It says that's required for third party and lob apps though, so I guess it's not needed for MS apps? ¯\_(ツ)_/¯
It seems odd that they would give you a drop down to select managed/unmanaged/all in the app protection policy, but then require a separate app configuration policy to add a setting needed to make that drop down work. The tool tip should explicitly state that additional configuration is required to make that drop down work as expected.