After having installed findus4 again it worked fine.
Then due to a lack of concentration I have overwritten custom.css.
I have rebuilt a code and it doesn't work:
.page-header h1, .page-header .h1, .categories-list h1, .categories-list .h1, .h1, .h1, .h1{
background: linear-gradient(180deg, rgba(255,100,0,1) 50%, rgba(247,5,5,1) 100%);
text-align: center!Important;
color:#fff!Important;
}
Before overwriting the code, facebook worked.
Now, as usual, it doesn't work.
Lack of consistency between Addthis and Joomla 4.
