Table header on mobile is broken

Hi,
I have an issue I didn’t have before, and I don’t know since when this issue is here.

On this page I have a table with a header :

And on mobile I have this :

Thank you for your help!

Edit : the images doesn’t seem to load, so here is a description.
On desktop, everything looks fine avec header, and on mobile, when the headers are duplicated, we see the html tag <STRONG>.

• This topic was modified 4 months, 3 weeks ago by Ariakan.
• This topic was modified 4 months, 3 weeks ago by Ariakan.

The page I need help with: [log in to see the link]