This is my last month of Sync Ultra sub. It's only a few bucks a month and Sync is relatively polished but I rather the money go towards a actively developed app.
Hmm by that last link it looks like sync isn't on the list of whitelisted sites. Granted, it's not a site, but an app. Seems like we need some kind of authorisation.
I had that issue a month or so ago, so I switched to Boost. It's not the same, but there's enough settings to customize it and make it close enough. Kinda a bummer, I've used Sync for many years, but Lemmy is evolving fast enough to require an actively maintained app.
If Sync starts getting regular updates again, I would probably switch back.
I frequently have that problem with redgifs on the website too. Even when I go directly to redgifs. Just earlier today, I was browsing and more than half the gifs I was trying to view failed to load, or were very slow to load. I've been having this same problem with redgifs for as long as redgifs has been a thing. I don't think the issue is with Sync, but with redgifs.