Lightroom has pixelated all my photos

Looking at your latest screenshots, the more complete ones, I notice a few things,

• In first screenshot we can see the camera make and model
• In the first screenshot we can see that the image selected is JPEG
• Cannot see in any screenshot the file location, but it may be assumed to be on a hard drive, not the cloud
• In the second screenshot we can see the History, and it appears the image was downloaded from the cloud, Via mobile.Also shown in filmstrip preview badge as those double arrows.
• First screenshot in Library, second in Develop-. By design, the Library is poorer at displaying the image, for performance reasons. I assume you know this and you are comparing only via the Develop module image.
• Third screenshot, I cannot see much difference, oh the width/height appears different, but that is a minor issue around real estate in use. 
• Difference between second and third display may not appear the same online on an iPad, vs on your monitor (scrolling up and down helps the eye see the difference)
  
  As to my point
• It appears that the image is not the true original, but a copy brought into LrC via an import from the cloud, apparently Adobe CC cloud. As such it is a degraded copy.
• Do you still have in camera SD card, the actual original. And is that RAW or JPEG, and either way, can you import it?
• Part of issue could be how image got from camera, to cloud, to LrC

An observation that has nothing to do with your issue or solution, but..

• In your Library Module screenshot. In the Folders Panel. I notice your iPhone is included. An iPhone is a flash media like an SD card, correct? Not to be trusted for long term storage, and can lead to accidental deletion.
• Are you actually using that iPhone as LrC photo media, or is that a leftover bit from some odd import done badly?

An odd inquiry. Treat this as in just in case, or to avoid an assumption.

• That third screenshot, the one outside of LrC. Yes, I see the same size file (may or may not be important, probably not). And you state from computers gallery, so perhaps the same exact file, but perhaps not. So, is the image selected in LrC and the image selected outside of LrC, the same exact file? Is one on a hard drive, the other in the cloud? The workflow involving mobile makes me ask.

And another inquiry that might as well be asked, how are you calibrating your monitor?

I might as well make the following request, it will probably be asked by other members, especially if you follow thru with that requested more complete screenshot:

Please post your System Information as Lightroom Classic (LrC) reports it. In LrC click on Help, then System Info, then Copy. Paste that information into a reply. Please present all information from first line down to and including Plug-in Info. Info after Plug-in info can be cut out as that is just so much dead space to us non-Techs and it takes up vast amounts of scroll space making the reply less readable and less likely that others will bother with your post. Also large amounts of text in a post also render the Translate function inoperable.

Hello!

I have been using Lightroom for a couple months now (my subscription covers Lightroom classic, desktop, and mobile) and recently all of my photos in Lightroom have become pixelated. 

This pixelation occurred seemingly at random, and happened to all photos I have in Lightroom - it had never been an issue before and I adjusted no settings around the time this began. It makes the photos more difficult to edit, as I typically zoom in quite far to remove small background objects, and the pixelation best be seen once you have zoomed in. The problem goes beyond editing, however, as my photos save with this pixelation as well.

This is happening on all versions of Lightroom I use (classic, desktop, and mobile), and is also happening in adobe photoshop. The issue persists even after entering 'develop' mode in Lightroom Classic. When checking upload status of the photo, it will claim that I am looking at the original RAW file, and not a smart preview. 

I will attach examples photos to this post...

These screenshots are from my phone, but the pixelation that occurs on my desktop is exactly the same...

Here is the first photo, saved to my device in February, before the pixelation happened. This is how my photos used to look when editing them as well, even while zooming in as far as possible:

The second photo is another zoomed in version of the photo above, but is an example of how my photos now look when editing them. Again, they look this way on all versions I use and this had never occurred before. 

And here is another good example of the pixelation...this is how my photos look when I save them. This is another screenshot of a zoomed in photo. (Again, on all versions, and regardless of whether I am trying to save to my phone or computer).

Please help! I have deleted all existing smart previews, and have messed around with export settings to try to get my photos to export at the highest available quality. I don't understand why this suddenly started happening and have now spent weeks trying to figure out how to fix it, but to no avail. I loved Lightroom before this began, but will have to cancel my subscription if I can't figure out how to resolve the issue, as this completely downgrades my photo quality.

I have no idea what to do! Any and all help is appreciated! Thank you in advance!