When using bndtools and baselining if the project bnd file has to have a version bump the only way to see why is going into the problems tab and hover over the error item. The project itself has the red x but the bnd file does not. Older versions would mark the bnd file with the x and then you could go into the bnd file , hover over the version and find out why bnd wanted to update the version.
I am using bnd 6.4 in eclipse 2023-03 (4.27.0) with Java 17