I had the same problem on lemm.ee when that admin upgraded it. In my case, it only happened when I was on Firefox on the desktop. It happened because I had Spanish installed as a display language.

If you have more languages than just English installed in the browser, remove them, close the browser, re-open the browser and see if it works. @https://lemmy.world/u/ruud, If you see this, ask @https://lemm.ee/u/sunaurus what he did to fix the issue on the backend.

I did a write-up on what I tried. My username is the same on lemmy.world as it is on lemm.ee.

I am also unable to login to Jerboa. I’m posting this from the desktop. I am logged into lem.ee on Jerboa.

I’ve experienced that several times, especially since, on desktop, I like to middle-click and open any link in a new tab. Then I have to copy that URL and paste it into the signed-in instance to subscribe or upvote

If you have an account at one instance, you can see everything from all of the instances that are federated with that instance. If there is another instance that is not federated with the 1st instance, then you have to make an account there to see anything there