In Jenkins ver. 2.176.2, user can access archived log files from Build Artifacts page and the txt file would word-wrap correctly.  In Jenkins 2.346.3, the same word-wrap feature is broken.

Text file is displayed within the following "pre" style:

<pre style="word-wrap: break-word; white-space: pre-wrap;"> .... </pre>

If I remove the style, word-wrap would go away which is expected.  In Jenkins 2.346.3, the present of the style setting in <pre> tag makes no difference.

Note that accessing the same log by appending /*view* at the end of the log file URL would cause word-wrap to work.  This /*view* string is automatically appended when click on the "Display artifact in new window" button but if click on the artifact file link directly would result in the word-wrap problem.