Hi Beynym, it's not just you. The platform only allows you to be logged into one community at a time. Logging in on the EN community does disconnect your sign-in from the FR or any other side. We know this can be difficult sometimes, and we're talking with InSided to see if there's something to be done here.
Personally, I use either multiple browsers or an incognito window so I can be signed in to multiple communities at the same time. I'll let you know if I hear anything about this changing.
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