I have the same issue. I installed bbp style pack plugin on BBpress 2.5.14. Forums were already set up. The only thing I really need is to change Forum Template to “Alternate Forum template 1”. It’s a must have for my client.
I click to select and save changes but nothing changes on the frontend, exactly the same. I use the free Customify theme but also tried the default themes with same result. I deleted cookies and cache but no joy. Deactivating all other plugins gives no joy either.
I also wanted so select option 3 in Forum Display to move the breadcrumb and that does work ok.