Ok, I have not had to deal with ceiling grids in years, but now it seems our light fixtures are not anchoring to the ceiling grid. Our actual problem is that the lights are showing in all plan views ( I am only guessing that the fact that they arent anchoring has something to do with this).
Im a bit concerned since both the ceiling grid tool and all of the lights are out of the box and reside on each individual machine and we are having these results across several machines.
Apparently enough people complained that even though they added a light fixture ten times, none showed up, and the out-of-the-box Plan display configuration(s) were changed to have lights shown (in addition to the RCP display configurations, which is what had to be set current previously, to get light fixtures to display). If you want things back the "old" way, you will need to edit the display settings to have them not show in Plan display configurations. (No time to confirm now, but if memory serves, you will need to edit the AEC Content files and then edit the Multi-View Block definition(s) therein.)
I believe that you will need to anchor the lights to the grid as a separate operation after placing them. Too many things floating around in my head at the moment to remember if it was always like that or not.
Funny, I was looking at the MVB and Masking Blocks earlier and noticing that the plan view had displays set. Im glad to know that its an out of the box thing and not a messed up library (though... how stupid is that!!!), and I suppose it could be argued that it is in fact now a messed up library. Well Im off to modify all those blocks.
FYI I think all of that changed, I pulled up an old 2007 project all lights anchored, and as I recall it was part of the insertion.