@Eyal Tzaig, Thanks for posting in Q&A. For the two affected devices, please ensure the following policy setting is enabled when deploy BitLocker policy from Intune to them.
Sync on the device side, Settings-> Accounts->Access work or school, the account, info, click sync to see if it can appear on Microsoft Entra ID (AAD) device record after some time.
On the other hand, you can try "BackupToAAD-BitLockerKeyProtector" to manually save recovery key to AAD device record.
Or you can also consider this script to do this.
Hope the above information can help.
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