I can’t export my presets in Lightroom onto my external hard drive. I just did the most recent update and now everything is either slow or not working. Any ideas?

“ to manually transfer … presets onto to a USB drive”   You can find your LrC Develop presets by-

a]  In preferences > Presets > [Show Lightroom Develop Presets], or

b]  [Right-Click]  a preset in the develop Presets panel and you can [Export] a single preset, or [Show in Explorer] 

In Mac Finder then copy and paste the [preset.XMPs] anywhere you want.

This is physically copying preset XMPs to another location- nothing to do with syncing.

As of April 2026 syncing of photos should be possible with all versions of LrC above 13.3.  Is your system syncing smart previews UP to the Cloud from Collections, or is it syncing photos DOWN from Lightroom (mobile versions)? And do you see any error messages- What shows in the Sync panel when you click the Cloud icon? https://helpx.adobe.com/au/lightroom-classic/kb/sync-faq.html

Exporting: Where are you exporting photos to? Are the destination folders available?  Does your system have full disk permissions?     FULL DISK ACCESS PERMISSIONS   Do you see any error messages? 

Your post raises three questions, but first what “Lightroom” app are you using- Lr or LrC, and version number?

1. “Can’t export presets”.   Presets (In Windows LrC) are normally stored in a Camera Raw folder (eg. C:\Users\{YourName}\AppData\Roaming\Adobe\CameraRaw\Settings), (unless stored with a catalog) and can be simply copied to backup or copy to another drive or computer using File Explorer or Mac Finder.
2. “everything is slow”.   That needs more details to assist a diagnosis.
3. “Sync keeps getting stuck”.  What and how are you syncing?