useMutation's `isPending` stays on `undefined` after calling mutate

return useMutation({
        mutationFn: api.Profiles.acceptFriendRequestInNotification,
        onSuccess: async (_data, { requestId, notificationId, metadata }) => {
                        console.log('IS SUCCESS'); <- this is logged
            ...
        },
        onError: () => {
            errorSnackbar(MUTATE_ERROR);
        }
    });

return useMutation({
        mutationFn: api.Profiles.acceptFriendRequestInNotification,
        onSuccess: async (_data, { requestId, notificationId, metadata }) => {
                        console.log('IS SUCCESS'); <- this is logged
            ...
        },
        onError: () => {
            errorSnackbar(MUTATE_ERROR);
        }
    });