NFC not working with some phones like iPhone 11

I am using nRF52832 SDK 15.3 and type 4 tag and some phones like iPhone 11 and Samsung S20+ are not able to detect the tag.  The tag works with other phones so I don't think it is a hardware problem.  I don't see the NFC_T4T_EVENT_FIELD_ON event.  I just see some NFC_T4T_EVENT_FIELD_OFF events.  I am doing initialization like this:

nfc_t4t_setup(nfc_callback, NULL);

Do I need to modify any parameters when initializing?