Specifically, firmware 2.1.0 will ignore overlapping programs — if a program is still running when a new program is scheduled to start, the new program will be ignored.
I’ve attached my exported config file corresponding to the programs preview comparison screenshots shown above. I suppose you could load this into one of your own OpenSprinklers with FW2.1.0 and find out how/why it displayed the way it did (queueing up overlapping programs) if, as you say, it was supposed to ignore overlapping programs.