Possible Save Bug in Sulani?

Product: The Sims 4
Platform:PC
Which language are you playing the game in? English
How often does the bug occur? Every time (100%)
What is your current game version number? 1.56.52.1020
What expansions, game packs, and stuff packs do you have installed? All EPs: Get to Work through Island Living; All Game Packs: Outdoor Living through Realm of Magic; Stuff Packs: Luxury Party through My First Pet. All free holiday content.
Steps: How can we find the bug ourselves? Move a Sim into Sulani. Play as usual for a few Sim hours (build a few skill points, find a couple of collectibles, etc, ). Save and then go into Manage Worlds or Main Menu and return to your Sulani save file and the Sim you were playing with. During the loading screen, you'll hear the little jingle you get when your Sim finds a new collectible shortly before the lot is loaded. And then you should encounter the issue where it's the whole week starts over again and your all of your Sims' progress is lost despite of being saved.
What happens when the bug occurs? After returning from the Manage Worlds screen, traveling via map, or even from the Main Menu, when I reload my save, I end up back at the the first day of the beginning of the week. All of the Sim's stats--skills, aspiration progress, inventory items, relationships, etc--are gone, despite of game progress being save prior.
What do you expect to see? All of my progress to save and remain every time I return to that particular save file, to continue where I left off at.
Have you installed any customization with the game, e.g. Custom Content or Mods? Yes
Did this issue appear after a specific patch or change you made to your system? Yes
Please describe the patch or change you made. I actually encountered a similar problem earlier with a file in Willow Creek once before. This was after the patch that came with the Moschino stuff pack. But at the time, I thought it was just a mod-related issue on my end and just scrapped the save. However, I decided to start up a new save in Sulani after I installed RoM its following patches. So, I'm thinking my issue actually started with the 1.54 August 8 patch.

‌

I've tried rolling back my saves, but strangely enough, even the recovered saves seemed to be affected, too. I've tried repairing the game twice. No bite there. I've tried a complete fresh, new save, same problem. I do use gigs and gigs of mods and CC, but I've long been pulled those out during my testing, but still ran into this problem. I've never had this problem playing in Sulani or any worlds until recently. It's a bit discouraging to because, now I'm walking on eggshells wondering if my other saves like Glimmerbrook and such are safe. 

If you need a save file or anything from me, I'll be more than happy to supply it to you. Any help or advice would be immensely appreciated!