Today I noticed a small icon to the right of each of my Moodle activities. I have never noticed this before. It's a small rectangle with the letter and number(s) F040. We are using Moodle 3.5
Are you using something else to copy and paste the titles from ... like from Word or other word processor to the box for the title some 'activities'?
For F040 See:
https://www.utf8-chartable.de/unicode-utf8-table.pl?start=61504&utf8=0x
So your moodle sites character set which might be utf8mb4 is seeing a utf8-unicode (?) for which there is no direct translation and thus the little strange icon.
BTW, best to copy and paste from a text editor and true ascii text ... not a word processing app on local workstation.
'SoS', Ken
It’s supposed to be the pencil icon (https://fontawesome.com/v4.7.0/icon/pencil) - clicking on it will normally allow you to edit the name of the activity. Which theme are you using? Does the icon show when you have editing on/off?