It's not a Warhammer novel, but feels very much like a police procedural featuring an Inquisitor's new apprentice helping to unravel a murder mystery in a seaside city that's also fearing the imminent arrival of a kaiju. Basically a cozy mystery set in the (old) Warhammer universe. It grabbed me immediately and I tore through it.
Also, I've see it in described as "hugepunk."
Available at Amazon, although I read it via the excellent Libby app.