Though 65 isn't really cold it is at the threshold of where I've had issues before. I like to print 68+f now, or warmer.
If you mixed from powder for this session it would probably have to be really, really, really old to be an issue.
Each developer has different capacity so consult the Mfg's info.
LPD is great, I'd heartily recommend it.
That said it would probably be hard to find a bad developer off the shelf.
I'd make sure you are a bit warmer and try what you have again.