The multirow setting "Automatic new row" is planned to be removed, it is recommended not to not use in new development, and to remove it from current implementations. The setting is removed since it gives a bad user experience.
There is no set date for when the setting will be removed.
Use the following query to see affected field infos:
SELECT
FICS.FieldinfoId
FROM
dbo.ADMINFieldInfoControlSpecific FICS
WHERE
FICS.SpecialfieldName = 'AutoNewRow' AND FICS.Value = '1'