You have to setup EMA on ALL your toons, not just the leader:
1. Invite your team to a group or raid.
2. Enable broadcast
3. Type in: /ema-team config
4. Click on "Add group/raid members to team"
5. Disable broadcast

Done. Now you can "push" settings between them.
Ignore the "sync with ISBoxer" function.

You may also use the DynamicBoxer addon that's doing some of the handywork to setup a new/change an existing team for you:
https://www.curseforge.com/wow/addons/dynamicboxer