|Never run into that symptom.|
See if it is normal if you go here:
If so a possible workaround is to save their homepage to IE Favorites bar (as a single click icon). If you are using another browser then there will be a similar feature.
About all I can suggest on the basic issue is to delete Bing in the search provider list then look for it again and add it back in. If something went awry that might fix it.
Always pop back and let us know the outcome - thanks