I also posted about it, but I played on medium difficulty. I encountered the same thing.Got to wave 23 when the timer didn't come up again. Sat around for a while and nothing happened. May just be because the waves are incomplete.
Quitting early doesn't seem to give any rewards, which sucks.
I just like to view most new posts and like based on constructive activity. I tend to "like" liberally on other platforms as well, like Youtube and Reddit.You don't have to like all my posts so much.