Hello, In Geant4 version 4.10.00.p01, there is a copy/paste error at line 612 of G4H2ToolsManager.cc. The result is SetH2YAxisTitle changes the title of the X axis of the histograms instead of the Y axis.
Thank you for reporting this. The problem has been fixed in the development version and the fix will be also available in the next patch to 10.0 release. Best regards,