for example wenn i enter 3000 and press enter, the sky elite shows me 500
This is not a SkyElite problem but an aircraft problem, some aircraft, not all, doesn't support entering a bug value by keyboard, and if you try then it shows weird values as you notice. When that happens use the arrows up and down on the keyboard, they should work better.
Test with other aircraft and you will see some work some others not. TBM 930 always worked for me but lately developers have been doing weird things with settings on some of the aircraft autopilot bugs and other things.
I have to guess that since they are using Working Title G1000 and G3000 lot of issues happens. Working Title instruments are great and nice, but they don't follow any SimConnect interface standard, which is the interface we use to connect to the Sim.
Please try and let me know.