The Cool SL Viewer v1.22 reacts in the exact same way as the official v1.22 viewer in this respect... This is not a bug.
Please, see the
rules for this forum. "Bugs" which are not specific to the Cool SL Viewer but are present as well into the official viewer should be reported on the official
JIRA (issue tracker). Note that this issue is not really a bug either... In mouse-look, all the floaters are automatically hidden, and since v1.21 the statistics "bar" was replaced by a statistics floater...
This is because Nicholaz' viewer is based on a much older code base. The Cool SL Viewer v1.19.0.5 also shows the statistics while in mouse-look, you may therefore use it for your testings (of course, the v1.19 branch, while faster on "old" computers, is slower on modern ones, but if you test all your weapons with the same viewer, this should not be a problem).