What Pk has said is true. What is happening is ye've reached the limit of markings. FH can hold at max capacity around 200 markings, I believe, so near the end of the line markings tend to either not work or show up as a previous marking. There's really no way of fixing this. If ye do wish to use those markings, ye'd 'ave to remove quite a few from the earlier markings on the list and edit a bunch of the marking.cfg to 'ave them work properly, but even then no one else would be able to see them the way ye do.
