Yes, Houzz seems to want to limit new users to Design Dilemmas. I used to visit the Texas Gardening and the Landscaping forums. To get back to these I went to my profile page, clicked on Following and clicked on a person who frequented Texas Gardening. After that I found a thread with Texas Gardening above it, the way your question has Florida Gardening above it. When I right-clicked on Texas Gardening and chose Open Link In New Tab, I got a page with all questions relating to that subject. I then clicked on Follow in the upper right corner. Hopefully, this will make it easier to return to, but I'm still figuring it out.

They want you to click around the site to increase their page views and get a better ranking on Google. Plus, they want you to see more ads, hoping you'll buy something. That's how sites are now.

Here's something I just discovered: click the 'Edit' link at the top right in the 'Your Topics' box and then you can scroll down in the window that pops up to see all the other G'web forums and select the ones you want to add to your topics list.