I know I’m still way at the beginning and cannot say much about the way WK works. But I do understand the feeling of frustration when it comes to language learning. Sometimes it feels like we reach a plateau that’s very hard to get out of.
As many have mentioned, it does help to review and consolidate what you’ve learned. If your accuracy has dropped to 50-60%, then it might be a good option to review those items differently. Personally, what has been really helpful is KaniWani and KameSame. Everyday, I do my WK reviews and right after go to KW and KS. It’s like a triple review and it doesn’t take time more than 20 minutes to get all these three done.
My accuracy had dropped, but after doing this consistently, it has picked up. Take your time and focus on really learning those items that don’t let you move forward. After a while you’ll have everything under control