Block editor Code and Preformatted failing to accept text

[seasoned_geek]

This file
​https://www.logikalsolutions.com/wordpress/wp-content/uploads/2021/06/u18-sources-list.txt

real name sources.list not that it matters. When I pull this into any text editor, be it on Windows or Ubuntu and select-all, copy, then paste it into either a Code bock or a Preformatted block it does this:

The end of the file actually looks like this in every text editor

# backports:
#
#   Software from a newer release of the distribution, or even from the
#   development branch of the distribution, but built against this release.
#   It may provide newer features, but should be considered untested.
#
#   Note: Software in this repository WILL NOT receive any review or
#         updates from the Ubuntu security team.
#
#deb     http://old-releases.ubuntu.com/ubuntu hardy-backports main restricted
#deb-src http://old-releases.ubuntu.com/ubuntu hardy-backports main restricted
#deb     http://old-releases.ubuntu.com/ubuntu hardy-backports universe
#deb-src http://old-releases.ubuntu.com/ubuntu hardy-backports universe
#deb     http://old-releases.ubuntu.com/ubuntu hardy-backports multiverse
#deb-src http://old-releases.ubuntu.com/ubuntu hardy-backports multiverse

There is also an annoying thing happening when I scrape Linux shell scripts into Code blocks now. The first line is against the left margin and every other line is indented one space. Does not seem to matter what editor I scrape from. At first I thought it was a Scintilla based editor issue, then it happened with Notepad on Windows and Leafpad on older Ubuntu distros. Leafpad is as basic as basic editors get. It supports no formatting.

I do not know if this cropped up earlier. I did not notice it until 5.7.2 but I might not have been paying attention.

I have a geek blog and post a lot of code so this is critical.

I have even switched themes in case this happened only in one theme.