Any slowness should be gone by now, I haven't seen the JSON thing happen to me yet, but I'll look into it. Next time it happens to you can you DM me a screenshot?
Thanks for looking into this more! A fix is in the works.
There's a known issue with any .website TLD, try adding this exception to your adblocker:
@@||*/pictrs/*$domain=lemmy.world
EDIT: It wasn't this- the problem has been fixed
I really considered something like tos., prequel. or even just reddit. but "old" gets the point across best.
Thank you for letting me know, it should be fixed now. Let me know if you encounter any other errors!
And we're glad to have you!
Watching Star Trek counts as self reflection and growth, right? 
...right?
Things may be uh- crispy for a few hours while we get re-Federated and all the other instances whallop us with traffic. It should pass within a day.
OP- you are not on StarTrek.website. You're on feddit.de. When you scroll /c/Risa you are scrolling a "copy" on feddit.de.
I assure you we are fully functional.
EDIT: FWIW I checked /c/Risa on feddit.de and thumbnails loaded fine ...maybe try clearing your browser cache?
I think I might have fixed it, let me know if you encounter it again.