Advice for not controlling the mantra

I have been doing 1 giant mind and i just finished the 12 step introduction.

At the beginning, by about my 3rd meditation I felt like i was getting pretty good at letting the mantra play in the mind without having to focus on it.

Recently I feel like i am getting worse at this... I understand that this is part of the process, but was wondering if anybody had any tips on how to keep the mantra playing without having to focus on it.

Thanks!