Slow Rendering Of Standard Previews in LR Classic 7.3

Why do my files that are rendered as Standard previews take such a long time? It takes a few seconds before I can clearly see if the image is sharp or not. It's very stressful to wonder if my images turned out every single I move from image to image. Initially I thought it was 7.3.1 so I reverted back to 7.3, but it's still the same. This issue is also apparent when cropping in on an image. After choosing my crop and pressing R to apply, the image doesn't look sharp until I click on the image to zoom in it, then click again to zoom back out.

I'm a weeding photographer that will edit over a thousand images for any particular wedding and the wait for each image to load properly or apply any changes is infuriating.