Filters 2.0 do not work correctly when displaying a label in a course.
I have created a simple filter:
function filter($text)

When text "world" is used in a resource, filter works as expected, but in label string "world" is replaced multiple times.
For a given text in a label:
"world"
filter will behave like this:
1. replace "world" with "world hello world!"
2. replace each "world" inside "world hello world!" with "world hello world!"

This gives the end result:
"world hello world! hello world hello world!!"