Normalize (and Loudness Normalization) - OK & Preview buttons are grayed out (on invoking the effect)

[petersampsonaudacity]

Describe the bug
When invoking the Normalize or the Loudness Normalization effects the OK button and the Preview button are both greyed out and the effect cannot be implemented on the selected audio.

This is a regression on 3.1.3 - and a regression on the previous alpha master that I have:
audacity-win-3.2.0-alpha-20220302+b7708d1-x64-msvc2022

To Reproduce
Steps to reproduce the behavior:

1. Purge the Audacity settings folder (to get OOTB factory settings)
2. Launch latest 3.2.0 alpha master
3. Generate default 30 minute chirp - default max amplitude 0.8
4. Effect > Normalize
5. Observe: the OK button is grayed out - and so is the Preview button
6. change the value in the peak amplitude box
7. Observe: now the OK button becomes un-grayed and available - and works

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots

Additional information (please complete the following information):

• OS: Windows 10 - but also reported on Linux by @SteveDaulton - so assume all OS
• Version: latest alpha 3,2,0 master - audacity-win-3.2.0-alpha-20220321+a994066-x64-msvc2022

Additional context
Simple workaround - but does not look good to the user

See also:
Amplify fails to default offer amplification to 0db #2700

[petersampsonaudacity]

This also affects

Loudness Normalization

[LWinterberg]

I'll note that the "(Maximum 0dB)" disappears when you check any button, and also that the unit text (dB / LUFS - see screenshot above) gets cut off before you resize the window.

[LWinterberg]

this has persisted across the recent UI change, see #3495 for screenshots

[Paul-Licameli]

Bisects to 652588d -- same as for #3234

[petersampsonaudacity]

Testing on W10 with latest 3.2.0 alpha - audacity-win-3.2.0-alpha-20220902+7c9c978-x64-msvc2022

Normalize and Loudness Normalization have the Apply button not-grayed-out and active - however they both still have the Preview button grayed out.

This means that VI users cannot Tab to access the Preview button.

[petersampsonaudacity]

Testing on W10 with latest 3.2.0 alpha - audacity-win-3.2.0-alpha-20220907+591f227-x64-msvc2022

@Paul-Licameli @LWinterberg @dozzzzer

This now appears to be working correctly on Windows - in both effects the Preview and Apply buttons are no longer grayed-out and inaccessible when invoking the effect.

[SteveDaulton]

The "Preview" button is still greyed out in Loudness Normalization.
Tested with Commit Id: 18d277 on Xubuntu 20.04.

[Ryan-Miller-Audacity]

Tested and verified fixed in latest alpha branch.