problem
Stereo reverb can create width with phase differences that become fragile when the mix collapses.
Many reverbs create stereo size by decorrelating the left and right channels. That can sound lush in headphones but lose energy or change tone in mono.
The problem is most obvious when reverb carries important vocal, snare, or lead instrument space.
Listen to the full mix in mono and watch stereo correlation while the reverb is active. If the dry source stays but the space vanishes, the return may be too wide or too phasey.
Solo checks help, but the final decision should happen in the mix where masking and balance matter.
Reduce reverb width, keep low-frequency reverb centered, and use pre-delay or EQ instead of extreme stereo spread when the source needs to stay stable.
Meter Core helps compare stereo width and mono behavior while you set space effects.