LR Classic has changed the way my photos look - the RAW images have weird blocky shadows
Just recently I've noticed that all my photos (Canon RAW - CR2) look a bit weird in LR and its the same in Library as well as Develop. The shadows all look very blocky and the light areas lighter than they should be. I have recently bought a new camera and it may have happened when I first started putting photos from my new camera into LR or it may just be a coincidence! I upgraded my old Canon 650D to an 800D.
I have attached 2 screen grabs showing an extreme example of whats happening from a blurry shot of a tree at dusk. The first image shows how the photo currently looks in Windows Explorer which is also how it should look. The second image shows how the photo looks now in LR. It also has the same distorted appearance in Photoshop.
Does anyone have any suggestions on why this has happened and how to fix it - many thanks!
Photo as seen in Windows Explorer - which is how it should look

Photo as Lightroom Classic now shows it

