haslador The inability to alt-tab is a known issue with the (now default) DirectX 11 version of Sims 4. Feel free to add your feedback to this master thread:
https://answers.ea.com/t5/PC/DirectX-11-Technical-Issues-and-Feedback-Thread/td-p/14022619
Feedback about not being able to play without an internet connection can go here:
For the rest, part of the trade-off of getting real improvements to this game, a full ten years after its release, is that sometimes things break. No software on the planet is ever released bug-free, no matter the publisher or the use case.
