View Toolbox disappears

Sorry if this is in the wrong section. I have not used this forum in quite some time, and the interface has changed to the point that I can't figure out where to post general MicroStation questions. 

Here is the problem - which I have had for quite some time. When using Microstation V on a Windows 10 machine. The View Toolbox appears, then after sing the program for a little while the tools disappear.  If I close the view window, and re-open it, the View Toolbox reappears. I can't tell if this is a graphics card issue, a Mstation setting, or a windows bug? I don't have this problem in any other program, but then again, I can't think of another program that has this feature?

Any suggestions appreciated.