What you were expecting to happen, and what actually happened?
This is an old issue and I thought it had been fixed. My defense team is being changed all the time to my attack team (ie, both my defense and attack are set to the troops I use for attacking)
What are the steps to make it happen again?
It might be related to playing both on mobile and PC (NOT at the same time)
Do you have any screenshots or video you want to share with us so we can see the problem? Attach them to your post!