Lightroom stays open after closing for a while after closing, and is using the network

[Inazuma]

App version: 13.5.1

Platform: Windows 11 Pro 23H2

Whenever I close Lightroom, the window will go but the process remains running for up to 15 minutes. And during that time it will also be showing network activity, transferring around 35mbps. What's more, it's not clear to me what/where it's transfering to because it doesn't match up with what's showing in Resource Monitor.

This is quite frustrating because I can't reopen Lightroom whilst it's still running in the background. And I dont want to close the process as there is a lock on the catalog until it's done. Anyone know what's happening?

[Rikk Flohr: Photography]

Do you have Sync with the cloud enabled?
If you pause Sync and then exit does the system continue to consume network resources?

[Inazuma]

No I have sync turned off.

I found out it was because I had enabled "Replace embedded previews with standard previews during idle time" and all my pictures are on a NAS. Still it seems to be a bug. It shouldn't continue trying to create previews after I've closed the program down.