EPG language sometimes incorrect

I have a channel, that has multiple languages and EPG. How can I force the grabber to pull the EPG data in the language that I need? It actually does it sometimes, but occasionally the EPG is pulled in a different language.

I am running Tvheadend 4.1-2052~g6b9dcab, and this has been an issue all the time on versions that I used. I don't want to upgrade currently, as the system is very stable currently, but if this is a solution I may evaluate that as well.