User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/113.0

Steps to reproduce:

With "Vertical" layout (tabs on the left, list of messages in the middle, message preview on the right) list of messages no longer has any columns.

I reported this in bug 1823019, but it got incorrectly de-duplicated with unrelated issue, likely because I have described it poorly.

Actual results:

Columns are gone since upgrade to Supernova

Expected results:

I have a very wide screen (thus vertical layout) and need columns just like "Wide" and "Classic" layouts have, at least as an option