[racket] another weird typed racket error

Here’s the program:
#lang typed/racket

(require plot/typed plot/typed/utils)

(: vsum ((Listof (Vectorof Real)) -> (Vectorof Real)))
(define (vsum vs)
  (apply vector-map + vs))

It’s giving me this error:
. Type Checker: Bad arguments to polymorphic function in apply:
Domain: (a b ... b -> c) (Vectorof a) (Vectorof b) ... b
Arguments: (case-> (-> Zero) (Zero Zero -> Zero) (One Zero -> One) (Zero One -> One) (Positive-Byte Zero -> Positive-Byte) (Zero Positive-Byte -> Positive-Byte) (Byte Zero -> Byte) (Zero Byte -> Byte) (Positive-Index Zero -> Positive-Index) (Zero Positive-Index -> Positive-Index) (Index Zero -> Index) (Zero Index -> Index) (Positive-Fixnum Zero -> Positive-Fixnum) (Zero Positive-Fixnum -> Positive-Fixnum) (Nonnegative-Fixnum Zero -> Nonnegative-Fixnum) (Zero Nonnegative-Fixnum -> Nonnegative-Fixnum) (Negative-Fixnum Zero -> Negative-Fixnum) (Zero Negative-Fixnum -> Negative-Fixnum) (Nonpositive-Fixnum Zero -> Nonpositive-Fixnum) (Zero Nonpositive-Fixnum -> Nonpositive-Fixnum) (Fixnum Zero -> Fixnum) (Zero Fixnum -> Fixnum) (Positive-Byte Positive-Byte -> Positive-Index) (Byte Byte -> Index) (Positive-Byte Positive-Byte Positive-Byte -> Positive-Index) (Byte Byte Byte -> Index) (Positive-Index Index -> Positive-Fixnum) (Index Positive-Index -> Positive-Fixnum) (Positive-Index Index Index -> Positive-Fixnum) (Index Positive-Index Index -> Positive-Fixnum) (Index Index Positive-Index -> Positive-Fixnum) (Index Index -> Nonnegative-Fixnum) (Index Index Inde in: (apply vector-map + vs)


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