S3 sync Region field input in Windows app is not updating

Operating system

Windows

Joplin version

3.4.12

Desktop version info

Joplin 3.4.12 (prod, win32)

Device: win32, AMD Ryzen 5 8645HS w/ Radeon 760M Graphics
Client ID: 11353ff8017c44d5b5602846cc3f95f9
Sync Version: 3
Profile Version: 48
Keychain Supported: Yes
Alternative instance ID: -

Revision: e9a9f68

Backup: 1.4.3
Freehand Drawing: 3.1.0

Sync target

S3

Editor

Markdown Editor

What issue do you have?

I did setup Cloudflare R2 S3 sync in Joplin. For the region my input was something like "Asia Pacific Region (APAC)" because this is how it shows up in cloudflare. But after putting this in Joplin, I got this error:
Completed: 08/01/2026 20:21 (22s)
Last error: InvalidRegionName: Could not upgrade from version 0 to version 1: The region name 'Asia-Pacific (APAC)' is not valid. Must be one of: wnam, enam, weur, eeur, apac, oc, auto

Fine, so I went and changed the region to "apac" and I tried the connection by clicking "Check synchronization configuration". It shows "Success! Synchronization configuration appears to be correct."

But that's not the case. When I click synchronise within the app, that same error appears again:
Completed: 08/01/2026 20:28 (25s)
Last error: InvalidRegionName: Could not upgrade from version 0 to version 1: The region name 'Asia-Pacific (APAC)' is not valid. Must be one of: wnam, enam, weur, eeur, apac, oc, auto

It is not catching the right info from settings.

Edit: I would like to add that I tried this word “apac” in iPhone app and it appears to be syncing flawlessly there with my cloudflare R2.

Screenshots

Does it make any difference if you try setting the sync target to none > save and then try reconfiguring the s3 sync?

if the behavior still doesn't change, if you look at the settings.json in your profile directory, does the correct value show for the "sync.8.region" setting?

I tried again after a day and in my surprise it fixed by itself not giving any error anymore. However, I am not receiving any syncing updates when I try to see the notes I make on phone would appear on desktop and vice versa.