Jungle Gin did not default to the lowest possible deadwood points when knocking

Hello, I have searched for an answer for my problem but can't seem to find anything so... I love Jungle Gin, I usually just play alone, (the standard, not custom) 100 pt. game with a bot. I encountered a strange occurrence the other day when I knocked with what I figured to be 3 pts. left in my hand. Instead of 3 pts. it said "knock with 6 pts." I thought the game would automatically default to the least amount of deadwood points but it did not. The case being that I had an Ace, 2, 3 of the same suit but I also had two other 3's making it three 3's in total. I would have counted the lowest deadwood being the ace & 2, but instead it defaulted to the run of A, 2, 3 and gave me the other two 3's as deadwood for 6 points! I still beat the bot but in the future it would be nice to know how the default settings of this game work. I've been playing on Pogo since 2002 and have never encountered this before. Also as long as I'm on here, is it common to have the "game cancelled" with only a few draw cards left? It seems I have played to what the game determines as a stalemate several times and it is frustrating to not see what the actual outcome would have been. Thanks for any answers you may have for me.