@tane
Just tested Technews 2.6.1.0 with the latest version of Publii with the current latest version of Apple macOS: no problems found – author page description displays as expected.
Which OS are you using?
Perhaps, under your authors list, choose an author, then in the Edit Author right-side panel > Description, in the mini-editor toolbar, choose the Source code button. You should have:
<p>Author description text here.</p>