Try to keep review sessions shorter.
If you realize you don’t recall the meaning of a kanji in vocab take the time to review the mnemonic for it again.
Don’t try to blaze through the twenties.
Put more energy into time spent learning new items. Repeat the mnemonics over and over.
I didn’t do either of these and wound up with 400 leeches with ever decreasing review accuracy that ultimately made me take a break from WK.