Redmine

I'm trying to use the {{collapse}} macro in a Redmine instance configured for Markdown formatting, with a custom text that contains a comma for the link:

{{collapse(This is a long sentence, separated by commas into multiple subclauses:)
test
}}

Unfortunately when this is rendered, everything after the comma is cut off:

This is a long sentenceseparated by commas into multiple subclauses:

Without commas it works:

This is a long sentence separated by commas into multiple subclauses:This is a long sentence separated by commas into multiple subclauses:

This is an unfortunate limitation because my native language is German which uses the comma much more than English, and this forces me to write grammatically incorrect sentences.