MSFS2020 objects floating while in max they are in place


Hi everyone! First of all, Happy Easter! Wish you a very pleasant Easter with your loved ones, fulfiled with love, happiness, joy!

Im working on a scenery for MSFS2020 and I have some trash bins like these on the image, but as you can see in 3ds max they are placed on the ground while in MSFS they are floating, they are all instances, some of them are floating, some of them are good in place.I have the same problem with some sign designators where some of them are shown (the base, black one) and somewhere are not present, they are also instances.I haven’t change anything like transform, just rotation, nothing else!

I have applied flatten polygon below the terminal but I got no luck.

Anyone maybe had similar experience?

Thank you!