Do a "Save As" duplicate of the troubled project. Sometimes that solves certain issues.

If that doesn't do it, try this: If waveform is forming, meters are active... Seems that it is not channeling through interface properly. Try going into Audio settings, selecting any "other" available device and switch back to your primary audio interface. By doing that you are resetting connection to Audio card without leaving BIAB session. I've had something similar in the past and this method helped me.