Windows 10: Taskbar Icons Disappeared

Back in November of 2015 I upgraded from 8.1 to 10. I run a two monitor setup.
The taskbar icons used to appear on both of my monitors, but now only appear on my secondary.
I've tried the option to have taskbar icons appear on all monitors. Doesn't work.

I should add when I move the task bar to the left, right, or top side of the screen the icons will appear on both monitors. But, when the taskbar is set to appear at the bottom, the icons do not appear on the primary display.

Any thoughts?

:)

 

taskbar disappears

While I am working most of the taskbar disappears and I have to push the up-down arrow icon in order to see all of the taskbar icons. How do you keep the taskbar from disappearing?

 

My taskbar icons disappear

I am using Windows 10. In my desktop I have icons in the taskbar. These open OK but when I close any icon the rest of the icons all disappear in the taskbar even though the task bar is 'locked'. There is a white vertical bar in the taskbar to the right
of the icons with up and down arrows. When the icons have disappeared if I click on the up arrow they all appear again. This is a pain having to do this everytime. What is the point of 'Lock the taskbar'. How do I stop these icons from disappearing?