In development mode, clicking on an ActiveX control will open a VB window - this is expected. In presentation mode, clicking on an ActiveX control will call your function.
If you want the version of this mode to open only in presentation mode (therefore, users will not be moved to the VB page), save the file as a PowerPoint Macro-Enabled Show (.ppsm). Then it always opens in presentation mode (save a copy in .pptm format for editing, but do not provide it to your users).
source share