@Raf,Thanks for posting in Q&A.
To clarify this issue, please check the following.
1.Did the iOS device onboard Defender for Endpoint?
2.Please follow the link below to check that the settings for onboarding iOS devices into defender are configured.
https://learn.microsoft.com/en-us/mem/intune/protect/advanced-threat-protection-configure
If there is any update, feel free to let me know.
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