Hello there !
Congratulations for this plugin which remains the best in its class!
This message is addressed primarily to those who have fallen on the same bug as me.
Here is my story (^ ^)
I first created a shortcode which will be called A.
I would have assigned a button in the TinyMCE edit bar.
It worked perfectly.
I created a second shortcode B.
I also assigned a button.
But when I traveled to the editor page or article, the two buttons did not appear.
Then when I désactivais shortcode button B, the A button reappeared.
At first I thought it was an incompatibility of plugins so I disabled all my plugins one by one, but it gave nothing.
Of course I checked my B button was properly activated ... I also tried rearranged the order of buttons in the menu for this purpose. But the bug persisted.
Anyway, I followed all the advice given on this support page. In vain.
So I'm doing something very stupid (but finally worked ... ask me why or how. When you spend five hours on this kind of bug, we no longer seek to understand ^ ^)
-> I edited the shortcode in it asisgnant A feature of the B.
Then I remove the shortcode B and I re-creates the shortcode A.
And it worked!
This was my story ...
At first, when I created my two shortcodes A and B, instead of two buttons in the TinyMCE edit bar, there was a button to insert tags <hr>. I never understood why ...
In short, I hope I have helped the world!