solve bot problem–unnecessary math captcha (Jetpack?)

We are using Memberpress for our site login. We’re suddenly getting emails from users that they’re having to solve a math question upon login and they get stuck in a loop that says “solve bot problem.” It doesn’t happen every time and everyone has so far been able to login after awhile. Upon searching, I see that there are a few closed threads about this same issue from last year that were apparently caused by Jetpack. We are using 3.9.6 of Jetpack. I’m going to deactivate it for now to see if that resolves it, but would still like to use it, so if there is a workaround, let me know.