Lightroom Classic 11.5 , JPG images on Import from Samsung S21 dramatically reduced in size

Hi

I had many JPG images imported from Samsung S21 Phone and in my Lightroom-Catalogue and on my Harddisk.

Now, suddenly their size has reduced from average 6MB to 80KB and the large images have disappeared.

When I import large images again from my Phone, I get a new image on the harddisk, again with the small size of 80KB. (On the phone the images are 6MB, I sent images by eMail from the phone and they have the right size).

I have activated the converstion to DNG on import, but this is not done.

Any idea what to do and how to fix this ????