String translations in English are not displayed anymore

Hello,

I have been using Polylang for 2 weeks now and it works fine.
I just noticed now though that the string translations for English are not displayed anymore.
They were displayed earlier today but now they are not.
In the meantime I have added these plugins:
– Social media and share icons (ultimate social media)
– Broken link checker
– W3 total cache

I have deactivated the plugins individually and all together but the issue persists. Any idea?
I have also deactivated Polylang and reactivate it but the result is still the same.

Here are some additional information :
– Permalinks settings: I’m using the article name
– I’m using a statics front page as my website uses a simple page theme (simplekey)
– I use EN and FR with 2 different domain names. and I have ticked the box “Media: translate the caption and description of your media.”

Thanks in advance for your help.

https://www.ads-software.com/plugins/polylang/