automation not working on bus

I am using the mute automation on a bus but it works only randomly. Most of the time actually it does not work at all. If I hit pause and play again then the correct status is used.

Mind that I do have the automation in “Play mode”

I have been using the mute automation on normal tracks without any issue.

I am using Ardour 4.7 on ubuntu.

any idea ?


anybody ever experienced the same ?
Just an additional info, I’m using ubuntu 16.04