automatically logged out of the launcher

Important my english is bad. !! 

I have been automatically logged out of the launcher for some time and have to re-enter my user data.  I already changed my password several times, but it did not get better.

This happens irregularly but mostly every two days. 

I have already written to the Minecraft support who can not help me so really.

 

I would like to write German in my native language but unfortunately German is not supported here. :C