Control bars missing when Advanced screen-sharing a "Second camera"

I host meetings and deliver webinars regularly using Zoom, PowerPoint, and multiple monitors.

(1) The floating meeting control bar is no longer available when "Advanced" screen-sharing to a "Second camera."
(2) This also causes problems when enabling captions.

Everything works normally when screen-sharing another screen.

Step 1: screen-share another screen

Success: floating meeting control bar is visible and Zoom windows are minimized

But there is no floating meeting control bar when screen-sharing a "Second camera."

Step 1: screen-share Second camera

A new sort of meeting window appears with meeting controls at the bottom.

Step 2: minimize Zoom windows

Fail: only the mini-window is visible, with minimal controls

Step 3: click the ^ icon

Fail: only minimal controls are now visible

Step 4: press ALT to show/hide controls

Fail: no controls visible at all

This also causes problems when enabling captions. 

For my setup, I need the captions to be floating freely on my monitor. But when screen-sharing to Second camera, the captions are contained within the Zoom window. If I minimize the zoom window, then the captions do float freely - however, I no longer have access to meeting controls (only minimal controls are visible; see above problem).

Step 1: screen-share Second camera

Step 2: enable captions

Fail: captions are contained within the Zoom window

Step 3: Minimize all Zoom windows

Success: captions are now freely floating; but Fail: meeting controls are now entirely missing

Troubleshooting attempts:

I have tried changing potentially relevant settings with no success. E.g. enabling/disabling dual-monitors, side-by-side view, always show meeting controls. I tried this on two different Windows desktops. I have tried unplugging webcams and other devices. I have restarted my computer. I have checked for Zoom updates.

Windows 11

Version 6.2.6