1.5.0 - viewer - metadata - Edit XMP makes file dirty

[user0]

XnView MP 1.5.0b1 64bits
Windows 64bit (22H2), display resolution 3840x2160, win scaling 150%

Viewer - metadata
Writing metadata via 'Edit XMP' makes file dirty (no issue with 'Edit IPTC')

To reproduce:
1. run clean portable XnViewMP
2. open jpg without any metadata in Viewer
3. open 'Edit XMP' dialog
- add something, eg Documen title
- press Write
image tab will show * sign
4. close image tab
'Save changed file' dialog will popup
- press 'Don't Save'
5. open jpg again
it will have new metadata and thumbnail will show xmp iptc labels in Browser mode

[xnview]

Thanks to your detailed description I can reproduce

[user0]

fixed in 1.5.0b2