After a lot of trial and error and a good bit of reading I have found the solution to my dilemma. It is not related to the Level Editor tab or dragging the Level Editor tab.
The issue is described in great detail here :
In-Editor Testing (Play & Simulate) in Unreal Engine | Unreal Engine 5.0 Documentation
In a nutshell my little game start/stop commands where stuck in “Simulate” mode and that prevented the PIP from popping up when I clicked start in the Blueprint window. All I had to do was change the setting to “Selected Viewport” and everything worked perfectly after that.
The setting causing me all the grief is fixed on this pulldown shown below. I suppose I probably accidently hit Alt-S at somepoint and had accidently switched it to Simulate. Ooops !!
Again, thank you kindly for taking the time to read and suggest alternatives.
This problem can be considered closed.
