In my last game, when advancing to the top of the science track, while having 9 science available, it asked me to confirm that I would waste science but it hadn't yet subtracted the 4 science that I was using to make the advance. After confirming the action I was actually only at 14 science.
Discussions
Bug: Confirmation for wasting science when advancing to last step
Thank you - an issue has been opened on github: https://forum.boardgamers.space/topic/191/bug-confirmation-for-wasting-science-when-advancing-to-last-step