What happened?

Description

Using the new 'Copy value from site...', the value from the other site is actually copied into a plaintext field, however after pressing 'Save', the new value is not saved and the previous value is still there.

Worth noting that the copy action does not trigger the blue changed indicator.

Seems to work with the native title field, and - fun fact - when in live preview.

Steps to reproduce

1. Have two sites with different languages
2. Have a section with custom plaintext field, set to translate by language or translate by site
3. Have an entry with different values for both sites
4. 'Copy value form site...' -> the text field shows the copied value
5. CTRL+S -> the text field shows the old value

Expected behavior

The copied value is saved.

Actual behavior

It is not.

PS.
This shows up when the little modal is opened:

No more JS errors when 'Copy' is pressed

Craft CMS version

Craft Solo 5.6.1

PHP version

8.3.16

Operating system and version

Linux 5.15.167.4-microsoft-standard-WSL2

Database type and version

MySQL 8.0.40

Image driver and version

Imagick 3.7.0 (ImageMagick 6.9.11-60)

Installed plugins and versions

• none