It sounds like you're just getting a bit tired from doing it all the time. Reduce the frequency of your observations and boosts in awareness, but focus more than you normally do when you look around, etc. Try WBTB if you haven't yet, or MILD. If you still aren't getting results, take a few days off and affirm to yourself that you'll get a lucid very soon.

...Why do I keep posting right after you, Mancon? xD