I'm seeing this also on certain features where it's not calculating bridging.
I have a 18mm wide gap in a wall that is 4mm wide and the slot is 2mm tall (I'm thinking this is the issue with such a small valley under the bridge). I removed the suggested supports as the bridge area is 2mm above the surface so laying support material in there is a waste This is a slot in the wall for a ribbon cable to come out. (Raspberry Pi Case)
I have changed everything in the settings and this example will not bridge (no yellow coloring). Funny thing is...... it does print ok... not perfect and has a little sagging (I cut that strand out because the first cross has infill between the 2 inner/outer wall lines).
I also discovered another bug during this that I will post separately (Dense Supports will not print with Support Print every-2 layers is on and the first Dense support is between that layer number).