buy bonus greyed out

buy bonus is greyed out for me lately, but only on some slots, not all. wondering if it’s a regulation thing or if it’s just the sites picking and choosing. i stick to the games i can analyze a bit, but sometimes i want to run some numbers on bonus buys for fun and can’t even get in.

this week i tried a bunch, even cleared cache, no dice. anyone else run into this? my “nope” list is already long enough, so just trying to figure if it’s worth chasing or if i’m missing a step somewhere. i’m not big on the auto-feature stuff, but i like having the option.