ACR uses special naming convention. See our support article for details here
However, this does not mean you cannot have contact names in ACR recordings. ACR provides two different ways to export/backup it's recordings.
Select few recordings by tapping on contact pictures on ACR, hit three-dotted menu on top, and select Backup. Recordings will be exported to ACRCallsBackup folder on phone the storage.
Connect your device to your local Wi-Fi network, go to ACR Cloud services and open Web Access. You can now open the address shown to download your recordings with contact names to your computer. Web Access feature is only active while you have it open and only accessible from your local network.