Wordpress frontpage not static

I could not reproduce the problem after downloading the Displace theme on a Wordpress test site. Need more information.

Thanks Tom

not sure what info to provide
the issue occurs randomnly
I have personnally experienced it during two of my browsing attemps

On each occasion where you experience the problem, is the URL pointing directly to the root directory of the site? In other words, there are no queries ("?") or category names in the URL.

I've  seen this on some themes where the home page is built into the theme and not an actual page.
either disable the "home page" in the theme settings or set the home menu item to "/" by using a custom link in the menu settings

Thanks Chiltern, I will try that

I can't disable the homepage in the theme's settings,
I can however avoid selecting anything for static page, but then I get the last post displayed as homepage

I tried creating a custom menu link, as suggested, but that doesn't seem to work. When browsing if I click on Home nothing happens

I had noticed last week that the theme's static page was set to 'Contacts'
I therefore corrected and saved the correct setting
Today I discovered that the setting had reverted back to 'Contacts' again !

I have sent a query to the theme's developper

I'm also wondering whether this issue could be linked to the WP version: 3.8.5 - I will ask the client why they haven't upgraded yet

PS
I didn't mention that the site also has a translation module (Ceceppa Multilingua)

if you website is in the root then
for the Home page menu to choose the root and not the home  "page"
 go to appearance - menu -
click on "links" on the URL  remove the http:/  and simply put /
on the link text put "Home"
click Add to Menu and move it into place. and save the menu.

for the home page appearing on the home page  try just have an empty page?

Thanks Chiltern

I tried it again just to make sure that I had done it right, but the "/"  takes us nowhere
I suppose it could mean that the site isn't in the root.

Funnily enough , I went back into the Theme's customization page and this time
there was another page in the the static homepage field (not Home, and not contacts)

situation solved by developper