This is caused by the lack of font files on the Linux server which deployed the JIRA .
Solution reference:
Prerequisite: JIRA 8.18 or above is required.
Step reference:
Log in to the Linux server which deployed the JIRA and find the directory: jira/jre/lib/
Create a "fonts" folder and a "fallback" folder in the directory: jira/jre/lib/fonts/fallback/
Copy the font file "hsc.ttf" to the directory: jira/jre/lib/fonts/fallback/
Restart the JIRA system