Lightroom Develop module changes my crop from 3:2 to 1:1 and I can’t retrieve lost pixels.

and I cannot retrieve the lost pixels.

So in the Develop module, when you click on the crop tool, and you change to Original or As Shot, you do not see a larger image with a undesired crop boundary, that you can just change?

More Screenshots may help.

Your Library module screenshot indicates an embedded image is in use for the preview, and I see a 3:2 crop. this imply the original data may be Ok. Wondering about the Smart Preview in use. does turning that off change anything?

And, in LrC preferences, in Presets, what do you have for RAW Defaults? A screenshot may help.

https://helpx.adobe.com/lightroom-classic/help/raw-defaults.html#:~:text=To%20set%20default%20settings%20for,from%20the%20Preferences%20dialog%20box.&text=Select%20this%20option%20to%20apply%20Adobe%20default%20settings%20to%20your%20raw%20images.

First, do you have the camera menu set to impose a square aspect ratio. Support for some cameras' Raw includes reading - or ignoring - the in-camera metadata regarding this, by imposing a nondestructive crop (which can then be changed to reveal a larger frame). And this support may vary by camera and also by LrClassic version. Some cameras offer a variable aspect ratio natively, and in this case the Raw itself may contain a different set of sensor data that's hard-cropped in camera to one or another aspect ratio (my much missed Panasonic LX100 was one such iirc). In that case this would operate just the same as happens with a camera JPG, where whatever you initially see, is all there is. 

Your photos of the screen were a little hard to make out, can I suggest you use the built-in screenshot feature of your computer instead? On Windows that is Win+shift+S, on Mac that is Shift+Cmd+5, and then you can drag a rectangle to capture the actual screen image and copy that to the clipboard. Then you can paste this image directly into your post so it appears within the text - not as an attachment. This is much more convenient for people reading your post; also, some people don't care to / don't risk to open attachments here.