Thanks a lot Davidfor, your fix seems to be working.
By the way, for other francophonic users, I realised that I also had the same problem with Kobo Touch Extended that got an update at the same time as KePub output. I posted in the appropriate topic.
https://www.mobileread.com/forums/sh...34#post4076334
Thanks again, happy new year and all the best for 2021!