1. What is the problem? Be very detailed.
It's hard to use ODK Central from a mobile device to configure others via QR code.
Two issues: the QR code is partly (landscape)or fully (portrait) off screen, so I can't scan it into another device running Collect.
Secondly, switching the mobile browser to desktop mode, I can view glances of the QR code and open the image in a new tab. Unfortunately, that image gets shown on a black background, which ODK Collect fails to recognise. Finally, saving the image and viewing it shows a white background, and bingo we can scan it.
The black background is likely an Android or browser thing, but I've been bitten so often by it that I suggest including a simple white border could fix this minor UX issue.
2. What app or server are you using and on what device and operating system? Include version numbers.
ODK Central 1.2.2
ODK Collect 2021.2.0 (latest of each at time of writing)
3. What you have you tried to fix the problem?
4. What steps can we take to reproduce the problem?
5. Anything else we should know or have? If you have a test form or screenshots or logs, attach below.