Displays settings: can no longer access controls once display set to 3x resolution

[cameralibre]

What Happened?

I have an external monitor, both it and my laptop screen work best on 2x resolution:

I switched it to 'Mirror display' so that I could present something to a group of people, and accidentally clicked 'Keep settings' without realizing that it had switched me to 3x scaling for some reason:

(The layout didn't not look obviously incorrect, I assumed the scaling was still 2x, but you can see in the controls that it says 3x)

Once I clicked 'Keep settings', both monitors switched to 3x scaling, which is basically unusable, but the real problem was that there was no way for me to get back to 2x. The Settings window was now taller than the screen, and I couldn't scroll down to the controls:

Disconnecting and reconnecting the monitor didn't help, because it remembered the mirrored 3x resolution setup each time. I had to disconnect and just present from my wee laptop screen, awkwardly turning it backwards and forwards 😅

Then later I looked up how to change screen resolution in the terminal to fix it.

Steps to Reproduce

1. connect a 3840x2160 monitor via HDMI to a 3840x2400 laptop
2. set scaling to 2x, and arrange the displays vertically stacked.
3. Save settings
4. Turn on 'Mirror Display'
5. The scaling factor increases to 3x
6. Click 'Keep settings'
7. Your setup is now unusable
8. Flail around trying to scroll to the buttons to fix it: move the window, try scrolling, try resizing the window...
9. Open a terminal and fix it using xrandr

Expected Behavior

1. connect a 3840x2160 monitor via HDMI to a 3840x2400 laptop
2. set scaling to 2x, and arrange the displays vertically stacked.
3. Save settings
4. Turn on 'Mirror Display'
5. The scaling factor remains the same.

But if—just for shits and giggles—you thought "let's see what 3x scaling looks like":

6. Change the scaling to 3x
7. It looks obviously terrible. Perfect.
8. Click 'Keep settings'
9. You immediately regret your decision.
10. You can scroll, move or resize the window in order to reach the controls. Or there's some 'reset to previous settings' option available at the top of the window. Or the controls themselves are near the top of the window.
11. Go back to your previous settings and be satisfied in the knowledge that you at least you tried living the 3x lifestyle, and it just wasn't for you.

OS Version

7.x (Horus)

Session Type

Classic Session (X11, This is the default)

Software Version

Older release (I have not run all updates)

Log Output

No response

Hardware Info

No response

[cameralibre]

I just noticed that I have not run all updates, I'll update now and re-test

[cameralibre]

Updated, re-tested, the issue remains.