Looks like the ones that are failing have a Null date. Try this expression.
if(
empty(items('Apply_to_each')?['New_x0020_Review_x0020_Date']),
null,
div(
sub(
ticks(formatDateTime(utcNow(),'yyyy-MM-dd')),
ticks(items('Apply_to_each')?['New_x0020_Review_x0020_Date'])
),
864000000000
)
)