recent and heavy lifetime cannabis use was associated with a statistically significant reduction in brain activity only during the working memory task.
That's a much smaller impact than the headline would lead you to think. If you're not a heavy user, or you're a heavy user but not for the past month, then you are unlikely to see significant mental changes. And even if you do, it's only for short-term working memory, no other types of mental ability.
I have never gotten WoL to work reliably in any condition. I would just assume it's not going to, and use other power controls.