Ignore the radicals and use something like the keisei (phono semantic composition) script instead.
I went through exactly the same frustration and it helped a lot. I think WaniKani’s radicals are useful early on when you start but become a hindrance as you start building a decent kanji inventory.
For one thing they obscure many useful phonetic components, like in your example.
I actually complained about this very kanji (among others) almost a year ago: It feels like WK somewhat loses its way partway through