I had the same issue and looked up the raw data in big query filtering all events by device.mobile_os_hardware_model where device.mobile_model_name is "iPhone". Result was ~99% iPhone13,4 and ~1% iPhone14,6.
According to following gist they are the internal ids for iPhone 12 Pro Max and iPhone SE 3rd Gen in my case.
https://gist.github.com/adamawolf/3048717
If you want to check on your side, go to https://console.cloud.google.com/bigquery and use e.g. following query (users with mobile_model_name = "iPhone" in last 7 days):
SELECT
Value AS Device,
COUNT(DISTINCT Id) AS Users,
FROM (
SELECT
user_pseudo_id AS Id,
device.mobile_os_hardware_model as Value
FROM
`<your_project>.<your_analytics>.events_*`,
UNNEST(event_params) AS params
WHERE
SUBSTR(_TABLE_SUFFIX,1, 8) BETWEEN CAST(FORMAT_DATE("%Y%m%d",
DATE_SUB(CURRENT_DATE(), INTERVAL 7 DAY)) AS string)
AND CAST(FORMAT_DATE("%Y%m%d", DATE_SUB(CURRENT_DATE(), INTERVAL 1
DAY)) AS string)
AND device.mobile_model_name = "iPhone"
)
GROUP BY Value
ORDER BY Device DESC
