Why doesn't downshifting work for 14-bit images?

[Lefi]

Dear colleagues

I have used the image property node with "16-bit Display Conversion Method" and "16-bit Display Number of Shifts" (see attached picture) to set the displayed image "intensity" for a long time. But when I got a new 14-bit camera, this stopped working. Or rather it works for 10-bits and 12-bits images, but when I display a 14-bits image, it stops working, even if I load e. g. a 10-bits images after a 14-bits image was displayed. Ideas? A bug?

[Lefi]

The funny thing is that if I save a 14-bits image from the new camera, restart my program and open the file, then I can use the downshifting. Without the restart it doesn't work. So it seems like images acquired with my 14-bits camera contains some hidden information that disables the downshift function.

[Lefi]

One more thing: When the 14-bits camera image is displayed, just the pixels close to 2^14 are white, as if the displayed image already was shifted by 6 bits.