Polylang Mantra

Hi there, and thx for the great plugin.
I use Mantra theme with a static front page.
I can’t translate the texts you write in the mantra settings.
Everything else works perfectly.
Any idea how, where I need to do some modifications so I can translate the Homepage ?
http://flightseven.ch

Thx in advance

https://ww.wp.xz.cn/plugins/polylang/