There's a bug affecting the customize homepage at the moment. To get your selections back, go to the forum homepage and click one of the "On / Off / Both" filter buttons as it may have deselected. That should restore your subscriptions to the homepage.
Here's what those buttons look like on desktop:
And on mobile:
Some users report they also needed to clear the forum cookie. https://www.digitaltrends.com/computing/how-to-delete-cookies/
There's also a bug affecting "empty" letters also (i.e. you don't have any "F" show subs) but that shouldn't have any functional issues, just cosmetic.