compressed JPG pictures get awfully deformed, can be salvaged, but still stay slightly deformed in dimensions

I use to compress jpeg pictures, and sometimes (not always), libreoffice will show either a blank rectangle, or wildly distorded and utterly illisible picture. Then, I save that blank rectangle or whatever, and insert it using the menu, or by droping in Writer the icon for the picture. Then, my picture appears as it should. But still, its dimension is slightly modified, compared to the original : the picture is flattened. Therefore I need to redimension it manually.

Has someone a clue about why LO does this on its own ?

I have exactly the same problem, but with any format picture. Most of mine are TIFFs and they completely distort with 75% of the picture disappearing off the frame, only displaying the first 25% all stretched out. It’s a disaster.