If you are shooting nature and want things consistent, sounds like it might be time to try out going to manual mode on the exposure, and even on the focus. I have access to an EOS R, but I find that manually focusing with a dslr is way easier than with the new digital viewfinders, but that could just be from a lack of experience with them on my part. Either way, give manual settings a try, especially if you are trying to capture the differences between the shadows and bright areas. I believe you can move the exposure lock to the back button. That might be what you are looking for. Get the exposure you want, hold the button to lock it in, then recompose and use the shutter button half press to let it focus. Then you can play around with where the focus point is in the frame to help ensure it’s focusing on what you want. Shooting moving cars required the opposite where focus was key and letting it meter the exposure right at the time the picture was taken was important. In your case, the focus isn’t going to be moving, you just need to nail down what it focuses on, and the exposure is what you are “chasing”. Which is why I would try out just going manual on the focus.
I would have to find my 5D book, but the issue there is that holding the shutter button down halfway also locks in the metering. So when you re-compose you have both the focus and metering locked. With the focus on the back button, you can separate the two, lock them to what you want, and then still re-compose the shot. My background was shooting racecars, so holding the shutter halfway and tracking wasn’t exactly something I could do. I could hold the back button down, and then just fire the shutter when I was ready. Lots of panning, so trying to be delicate with the shutter button wasn’t really a good idea for me when things got moving.
I usually remove the focus lock from the shutter button and put it on the * button on the back of my Canon bodies. I don’t have an R50 so I can’t tell you how to do it exactly on that model. This allows you to get focus, and then lock it in and recompose the shot without having to worry about the camera “deciding” that you want something else to be the focal point when you press on the shutter button. Just my quick opinion and there’s a ton more to focus settings, but that’s always been the first thing I adjust on my Canons.
I don’t know what buttons you can remap the focus to on that model camera. I just know that I have my 5D mapped to the back * button, and have been doing that back to my 10D days.