Sims in very dark shadow

Product: The Sims 4
Platform:Mac
Which language are you playing the game in? English
How often does the bug occur? Often (50% - 99%)
What is your current game version number? 1.47.51.1220
What expansions, game packs, and stuff packs do you have installed? Everything except Get Famous, Vampires, Backyard Stuff, First Pet, Kids room stuff.
Steps: How can we find the bug ourselves? Not sure, visit different lots perhaps.
What happens when the bug occurs? Noticed it most often when visiting other lots.
What do you expect to see? Normal shading.
Have you installed any customization with the game, e.g. Custom Content or Mods? Not now. I've removed them.
Did this issue appear after a specific patch or change you made to your system? Neutral/Not Sure 

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My Sim was visiting a household lot. The view from the other side looking towards the house I could see them all, they were all in normal light. But when I turned the camera the other way, with the house behind the Sims are all really dark so I can hardly see them.. They are also dark all over, rather than just one side of the body, as you would be when standing in shade. You'd be lighter on one side and slightly shaded on the other. I thought that it could be due to the house being behind them, casting a shadow. But if so it's making them extremely dark, and it only seems to affect them and not any other objects. 

It's possible that this started to happen after I installed Seasons, as that was the most recent expansion pack I purchased. I don't seem to remember seeing it before then.