Maybe it’s a problem with the cached data - can you try to clear the cookies and site data for EO Browser? (instructions, if needed)
If that doesn’t help, can you turn off Firefox extensions and try if the problem persists (maybe some extension got an update that is causing problems)?
If the problem persists, can you also try to open it in a private window or in other browser? (EO Browser unfortunately doesn’t work good in Internet Explorer)