It's possible to set a block layout to have a fixed width, but not include a value

[jameskoster]

When you switch to 'Fixed' from the other options the text input is empty, and no fixed value seems to be set on the frontend.

This makes the fixed width option feel a bit buggy.

One solution might be to treat the inherent width (IE the width if set to 'Fit') as a fallback, which the input will be populated with even if left empty.