Refresh problem site for different lang

I have a strange problem on this site :
https://www.kim2015.it/
click on EN link, below in the footer area, it opens the right url https://www.kim2015.it/eng/ but the menu labels and the footer text remains in italian language, if I refresh with F5 the page all the text are shown rightly in english, the same happens in english version click to italian version.
I don’t know who to fix this problem

Anyone can help me?!!

The .htaccess file for italian versione is this :

# BEGIN WordPress

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

# END WordPress

for the eng
https://www.kim2015.it/eng/ :

# BEGIN WordPress

RewriteEngine On
RewriteRule .* – [E=Cache-Control:no-cache]
RewriteBase /eng/
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ./eng/index.php [L]

# END WordPress

The hosting space does not report errors

thanks