Add / Remove Host with Keynotes

[PhilvK]

When placing a keynote the Add/Remove button appears, but when I try to select another host it pops up another tag. If I select an existing tag, the Add/Remove button does not appear. Am I not following the proper sequence?

[RDAOU]

@PhilvK 

I am not sure if I could explain it better in words...maybe this GIF would help

[PhilvK]

I got it to work like that once with a Beam Tag, but still can't with a Keynote tag. I'll keep trying. Thank you.