Twentig editor shows wrong page width

When editing any of my existing webpages everything is centred in the middle third of the page with a wide margin each side. However our website is still correct. I can fix the problem in the editor by changing the alignment of each block for “None” to “Wide Width”. However it would be very time-consuming to do this for every block on every page!

I suspect that the default alignment within the editor has changed but I can’t find where it is set.

Another issue is that the highlighting colours have changed. I create Groups containing Heading text and Paragraph text. I colour each group in a pastel shade but that means that text with links doesn’t automatically show red, so I highlight it to change the colour to red (I use the plug-in Block Editor Colors to extend the range of colours available). However in the editor this highlighted text now shows some other colour even though the website shows the correct color.

I have a document that illustrates the problem but can’t see how I can attach it to this message

I’m using WordPress 7.0 with the Twenty Twenty-One theme (version 2.8) and the Twentig plug-in (version 2.0.1) to extend the options. I suspect that the latest update of Twentig is causing the problem