This has been reported before but I haven't found a definitive resolution posted.
I'm using version 18.104.22.168
I can set up a series of buttons and they will work but from time to time the first button reverts to it's default settings ie labeled "Start", default size, allocated variable "INTERFACE_START" etc. I have not seen any other button transmogrify.
I don't know if this is relevant butting looking at the .robo file, the button definition list is pretty chaotic - instaed of each button's settings being in order, they appear thoroughly mixed up.