A/B comparison not working in VFB

If I try using the A/B comparison in the VFB history, I get a black screen with “not rendered” Sample image attached shows just one snapshot loaded up, but the same happens if I load something into the B, or into both A and B.

(If I use the resume rendering icon from the snapshot, it seems to do that just fine).

This seems to be working normally now in Oct 31st build!