Is there any way to sync to a specific device anymore? Or is the only way to do it by doing it on the device itself?
That’s correct. You can only trigger a sync from the device to which you want to sync your media.
Ok thanks! Does that mean this guide is out of date? Quick Guide to Mobile Sync | Plex Support
Yes and no 
The article refers to the old Mobile Sync feature. The current clients have all transitioned to the newer Download feature.
https://support.plex.tv/articles/downloads-sync-faq/
The guide isn’t so much outdated but obsolete.
Ah ok. I can’t seem to find the download option when using Plex from my tablet. There’s only a sync option, which then syncs a movie I pick but never downloads it or puts it on the actual tablet. Is the sync on the tablet just an option that doesn’t work? Basically, I want to be able to view files offline on a mobile device.
Ok, looks like I was using an older version of the player on the tablet. Now the download function is there, but when I press it, nothing happens. Do you know why that might be?
Here’s a thread dealing with a number of issues the new version had. From what I’ve seen, most should be fixed but some could be linked to specific aspects of your setup / home network.
Ok thank you. Do you know if it’s possible to use older versions of Plex server?
Possible? Sure.
Recommended? Probably not.
