In Row layout, when you open a message, the search bar disappears, it's replaced by a toolbar. To search again, you have to go back to the list first.

And most of that toolbar is redundant: mark as unread, delete, move and label are already in the message's own toolbar, just below.

Suggestion: keep the search bar visible at all times, like in Column layout (and other webmail). The few actions that are only in the top toolbar (back, archive, spam, previous/next) could sit next to it, or move to the message toolbar.

Like a few other small annoyances, it's unnecessary friction in daily use. I sometimes wonder whether it's a deliberate choice to be different from other webmails, or if proton team don't really use the product.

Thank you