I'm sorry. Disregard. I realize now that the whitespace-mode is affecting the buffer-display-table.

From: Ben Sferrazza
Sent: Sunday, January 2, 2022 11:57 AM
To: bug-gnu-emacs@gnu.org
Subject: whitespace-mode prevents (set-display-table-slot standard-display-table ...) setting correctly

Emacs 27.2 on CentOS 8 in terminal -nw mode

If whitespace-mode is enabled, setting standard-display-table characters such as

(set-display-table-slot standard-display-table 'vertical-border ?\u2503)

doesn't proper apply. This occurs if these is set before or after whitespace-mode is enabled.