LH is quite a bit outdated with the functions.

In the past (some years ago) every booking that had the M&M Number attatched would show up in the online booking list. This has been enhanced away.

Then you could add a booking manually.

On other airlines the system is much better.
QF shows every booking with my Frequent-Flyer number.
If not, I can add it and add my frequent-flyer number.

BA lets you change your booking, cancel it, add/change a frequent-flyer-number, change your seat-reservation rebook and upgrade your booking no matter if it was booked online or in a travel agency.

LH may be ahead with the mobile boarding pass, but with all the other features it is still stone-age!