I made a video that shows the error, but it looks like I have to put the video on the web before I can post it. I'm already late for my bike ride and need to beat the upcoming heat.
Here is the link to the video that I made to replicate the issue the OP asked about. It's weird, though, that I can replicate exactly what was posted by the OP Zaffer while BarbBinder, jbm007 , @Dave Quail cannot. I ask the three of you to watch this video and tell me why it behaves normally for you.
Do you actually click tools while you are in the 3D workspace? That appears to be what triggers the bug.
http://www.monarchtraining.net/images/3D_workspace.m4v
00:00 Essentials workspace, tools normal
00:02 3D workspace; don't click any tools
00:13 Essentials workspace, tools normal
00:25 3D workspace; click eyedropper > click paint bucket > click move tool
00:39 Essentials workspace: eyedropper is material eyedropper > paint bucket is
material drop tool
This is a bug, I think—these two tools should return to normal as they did in 00:13
00:53 I reset all tools to return the Essential workspace to the regular tools
Zaffer does this video replicate your problem in your original post? If yes, then I think you discovered a bug.