Any ideas why TRPC doesnt find the mutation?

import { z } from "zod";

import { clerkClient } from "@clerk/nextjs/server";
import { filterUserForClient } from "~/server/helpers/filterUserForClient";
import type { TeamMember } from "@prisma/client";

import {
  createTRPCRouter,
  privateProcedure,
  publicProcedure,
} from "~/server/api/trpc";
import { TRPCError } from "@trpc/server";

export const activityRouter = createTRPCRouter({
  startRace: privateProcedure
    .input(z.object({ id: z.string() }))
    .mutation(async ({ ctx, input }) => {
      try {
        const race = await ctx.prisma.race.findFirst({
          where: { id: input.id },
        });

        const createMany = await ctx.prisma.activeTask.createMany({
          data: [
            {
              taskId: "clgzk25a30000q74rrov7jvnm",
              teamId: "clgzep8kl0000q7vkbngr1ecm",
            },
            {
              taskId: "clgzk25a30000q74rrov7jvnm",
              teamId: "clgzep8kl0000q7vkbngr1ecm",
            },
            {
              taskId: "clgzk25a30000q74rrov7jvnm",
              teamId: "clgzep8kl0000q7vkbngr1ecm",
            },
          ],
          skipDuplicates: true,
        });

        return createMany;
      } catch (error) {
        console.log(error);
      }
    }),
});

export const appRouter = createTRPCRouter({
  race: raceRouter,
  team: teamRouter,
  location: locationRouter,
  task: taskRouter,
  activity: activityRouter,
});

 ❌ tRPC failed on activity.startRace: No "mutation"-procedure on path "activity.startRace"