Employment Record Missing

I have quite a few employees complaining that our employment isn't showing on their gov gateways, they are on the FPS, NI, address DOB all match up but still not showing on the hmrc site, any reason why? It's a reoccurring thing, old employees and new employees constantly complaining about this issue, new employee requested it online 8 weeks ago, i wrote a letter 4 weeks ago and still nothing has changed

Hi Emma Mayfield,
The individual employees may need to speak to personal tax on 0300 200 3300 to check that the payroll information is being attached you their NI record.
Thank you.