Sidebars not shown on tablet

hi cats,

how is it possible that when I have a page with left and right sidebar that on my laptop I see both sidebars (widgets I placed text and one with a photo)
on my tablet I only see left sidebar???

strange thing is that on top of the website I placed a link for facebook and that is shown on my laptop and my tablet.

so the full width of the website is shown.
is there a setting I did’t think of.

best regards,
franklin