Hi Bep, I thought I might have seen an issue reported recently where “autoprefixer” could not be found with recent versions of nodejs and npm. I cannot remember the issue reference. However, I believed I resolved this issue same issue through the use of the PostCSS options mentioned in my last comment.
Further details, if they are helpful are that I have all npm modules installed globally, not locally and was using a standard “postcss.config.js”. I’m using Node v16.14.0 and npm 8.3.1.
I thought I’d mention this in case it might be of any help. I happened to try it after my Ubuntu rebuild and got lucky. Thank you once again for all of your help on this wonderful forum. Much appreciated. Cheers.