Esperanto uses a comma before a subordinate clause. Apparently this is how many European languages work. https://forum.wordreference.com/threads/comma-before-a-subordinate-clause.752281/
There is something called "the 16 rules of Esperanto grammar" but it would be silly to actually think that you can have a real language with just 16 rules. If anybody is promoting Esperanto by saying that, they should stop.
If you said this out loud would you pause at the comma or is it only recognized when writing in Esperanto?