@vladnc It looks like the thread was reorganized so that your initial post, where you said you'd fixed the problem, could instead be the solution. If you don't want it marked as solved, let me know, and I'll unmark it. (I know you kind of said so, but I'd rather double-check before doing it.)
You don't need to make a new thread, and I don't think bug reports is the right section anyway—that's really for in-game issues, not broken features that accompany the game.
Anyway, I tested this just now, and I was able to bring up the bundle screen as long as I had Origin in-game enabled for Sims 4, whether or not it was enabled globally. So the issue is likely either your system or your connection. It might just be easier to buy through the Origin app or website rather than in-game, since it's not clear exactly where the problem is. If you do want to troubleshoot though, here's how.
For a connection issue, the fastest test is to use your phone as a mobile hotspot; make sure it's using data, not your home wifi. You don't need to use it indefinitely, just long enough to test the bundling function.
For a system issue, please clear the caches for your default browser and for Internet Explorer. Even if you never use IE, Origin still apparently does for some purposes. Be sure to uncheck the box to preserve data for favorite sites.
https://kb.wisc.edu/page.php?id=15141
If that doesn't help, please clear Origin's cache and uninstall it "the hard way"; a regular uninstall leaves behind a number of hidden files.
https://help.ea.com/en-us/help/faq/clear-cache-to-fix-problems-with-your-games/
https://help.ea.com/en-us/help/origin/origin/manually-uninstalling-origin/
Restart your computer, download the full installer, and run it as an admin: right-click on the download and select "Run as administrator." This is a direct download link:
http://download.dm.origin.com/origin/live/OriginSetup.exe
Restart your computer after installing and before launching Sims 4.
