Plasma 5 questions

I added a panel to the top of my screen to hold widgets for my frequently accessed apps. I set it to autohide but it stays put. I had a similar one in KDE4 that worked.

I have the same, but I use Tumbleweed.
Only difference I notice is it doesn’t auto hide until you mouse over it.
And the effects of reveal and hide are not as smooth as with kde4

To clarify
I mean when you login the panel is revealed and you have to mouse over it for it to hide.
After that it works normally.

My bottom (default) panel works that way. The top panel stays put.

There was a bug regarding auto-hide, but that should be fixed already IIRC.

What do you have in the panel?
If a plasmoid (or application) requires attention, it will prevent the panel from hiding.

I have Firefox, Thunderbird, spacer, LibreOffice word, calc, impress, base, spacer, Dolphin, Calc. It is in the center of the top edge occupying a bit over 1/2 of the width.

Those are standard application launchers, i.e. “Icon” widgets, right?
They should not prevent the panel from hiding then.

I created a second panel on the top edge here as a test with some such launchers and spacers, and it shows/hides correctly.
I’m using 5.3.95 (5.4 Beta) though.

At this point I can only suggest two things:

In my instance of 42.1 the bottom panel pops up and stays up every time I change from one window to another or minimize a window. The panel hides when I mouse over it. I’ve checked the panel settings and autohide is selected.
Plasma 5.43; Qt 5.5.1; kernel 4.1.13-5; on i5 CPU
Possibly relevant: The lightbulb on the desktop background and a dosemu window appear stretched wide, but only some times. At this time the desktop is stretched but not the terminal window.

One more point:
The system tray also pops up when looking at the Network widget and does NOT hide when I mouse over. The tray conceals the buttons at the bottom of the Network window, making them unusable.