This has been my experience as well. Hopefully this is something Apple can improve upon.

Just ran into this (Swift module used in Objective-c Framework then used in Swift). Did you ever find a solution?

Found the solution, add: -Xcc -fmodule-map-file=$(GENERATED_MODULEMAP_DIR)/<YourSwiftModuleImportedFromObjC>.modulemap To Other Swift Flags.

Did you ever find a solution for this?

I'm passing in kSecAttrAccessibleWhenUnlockedThisDeviceOnly. But I've thought that could be the cause* and also tried kSecAttrAccessibleWhenUnlocked, kSecAttrAccessibleAfterFirstUnlock and even kSecAttrAccessibleAlways. The issue exists no matter what the protection is. *since all the Macs that exhibit the issue are on 10.12 but also don't have a Secure Enclave (Intel Macs without T1 or T2 chip). I've also just filed FB12189765. There's a sample project attached to the feedback. I can't seem to attach a zip here but I'm attaching the relevant code as a .txt for reference here. ContentView.txt