A few ideas:
Glasses can start to show crosstalk as they get low on batteries. Try a fresh pair. Even with new glasses, sometimes they're shipped with bad batteries. I thought my first DLP-link glasses were defective, until I tried putting in new batteries.
Sometimes you can see crosstalk out of the top or bottom edges of the glasses. If you've recently moved closer to your screen and/or viewing high contrast content you might just be seeing something you never noticed before. I have NEC DLP-link glasses but they look exactly like the Optoma zd101s (quite likely the same glasses rebranded), and I noticed some crosstalk due to this when playing Mass Effect 3 sitting very close. Moving back, moving my head to look straight at something, or playing a different game solved it.