UE5 does not let me import a heightmap, PLEASE HELP

Hello, please help.

For some reason I cannot import a heightmap into UE5. I am following the tuts, do everything they say, follow every single step precisely, and then on import the engine says that either ‘File type not recognized’ or 'File doesn’t have proper pattern (ex:_x0_y0.png)
image

image

I have tried 16 bit, then when it did not worked I tried 8 bit, I tried saving it in .PNG and in .RAW, I tried RGB and grayscale, - NONE of this worked.

However, if I download some image from the internet - it lets me import it nice and smoothly. If I re-save it with photoshop with 0 changes done - it fails to recognise it again.

Somehow I managed to import the test heightmap from photoshop by a blind luck - and it did not let me to re-import it afterwards. I also tried to export it, and it got exported in the form of several images:


each of them is accepted by UE5.

Can you please tell me, what should I do to normally import any heightmap pictures from Photoshop, as a part of normal workflow?