XnView Software

Version 1.7.0

To reproduce:
- open an uncompressed TIFF
- Properties with Alt+Return: "no compression" (correct)
- "Save as tiff with compression"
- Properties with Alt+Return: "no compression" (NOT correct)
- close and open the tiff
- Properties with Alt+Return: "compressed with ...." (correct)

Or:
- open a TIFF
- Properties with Alt+Return: "Image Format: TIFF" (correct)
- "Save as JPEG"
- Properties with Alt+Return: "Image Format: TIFF" (NOT correct)
- close and open the JPEG
- Properties with Alt+Return: "Image Format: JPG" (correct)

please send me sample files

I don't think that it is depending on the file. I attach a screenshot, made by XnView - and it does the same.

i can't reproduce, Properties show properties for current file.

related
1.4.5 - viewer - save as - original image remains open once saved to another folder