need help: teleport -> crashes client (sometimes)

when i teleport a player anywhere where he is surrounded by blocks (only the 2 blocks for the player are air), he will be teleported to the highest block at that location, instead of the location i tried to teleport him, and crashes the client and/or kicks him cause of too fast moving





sideview (sheep = player)


source is in the jar (if someone wants)
how to config


with these +0.5 and +0.3 i wanted to be shure that the player will spawn in the middle on a block and not in or in the wall, if i correct Y with +0.2 the player will stuck in the block below

to.getY()=123.3
player lands at: 128.3

Code:

Location to = new Location (destWorld, Math.floor(X *worlds[i].dm) + 0.5, Y+0.3, Math.floor(Z*worlds[i].dm)+ 0.5);
player.teleport(to);
event.setTo(to);

worlds is the actual connection, dm is the distance-modifier (int) (loaded from config.yml)
Y is the hight, also loaded from the config

before the one above ...

Code:

                       if (worlds[i].cobW2) {
                           if (worlds[i].typeW2)
                               Y=plugin.s1.bedrockceilingarrival;
                           else
                               Y=plugin.s1.airceilingarrival;
                       }
                       else {
                           if (worlds[i].typeW2)
                               Y=plugin.s1.bedrockbottomarrival;
                           else
                               Y=plugin.s1.airbottomarrival;
                       }

so the result is if i teleport from a normal world (bottom) to nether or cavemap (ceiling) or back, the Y is ok, its what it is supposed to be, but the player lands only on the highest block at this location
i have a function that sets Y to the highest block at that location, but i isnt called if there is bedrock or the destination is at bottom

so when i make the Y as output it looks like this:
5.0
4.7....
4.2...
3.4...
you have arrived in nether
123.3
123.3
... (5 times)
and then:
123.28125
128.3 <-- !!! why??

i think i have to workaround again and make this: