Ok so, 2nd time out in the new 384BQOK. First time was an overnight stop at a KOA on the way home from picking it up. This time was 4 days at a state park. Anyway, dumped the black tank at the front and went to flush it but nothing. There are 2 connections for flushing. One for the front and one for the rear black tank. Anyone know which port is for which tank? Maybe I had the wrong one. The upper port did nothing. It’s like it is capped off on the back side. I’m attaching a picture. Thanks in advance for the help. My Forest River Sierra manual doesn’t cover this. Oh wait.....What manual. Lol.