Welcome to the forum, Machine1k.
I had the same sort of problem in my game, where it would try forever to save and the only way I could end it was to use task manager to shut down the game. In my case, this would happen after I used Buy Mode or Edit Town. I contacted EA and they recommended that I do a factory reset. I did, and so far the problem appears to have been fixed (fingers crossed that it will continue).
Another issue that has been reported to cause save problems is rain puddles, so if one of your new EPs is Seasons, that might have something to do with it. It's not always easy to know what's causing the problem or what to do about it, but at least you know you're not the only one to experience the problem.
Both the factory reset and the save problems related to rain puddles have been discussed in different threads here in the forum. I don't have the links just now, but they should be easy enough to find if you try a forum search.
Good luck, and I hope you'll enjoy the forum.