Strange behaviors of match's or pattern

What version of Racket are you using?

v7.8

What program did you run?

Program 1:

#lang typed/racket
(define-type Type (U Number Symbol))
(ann (lambda (arg)
       (match arg
         [(or (? number? x)
              (? symbol? x))
          x]))
     [-> Type Type])

Program 2:

#lang typed/racket
(define-type Variable (Refine [var : Symbol] (! var 'λ)))
(define-predicate variable? Variable)
(define-type Type (U Number Variable))
(ann (lambda (arg)
       (match arg
         [(or (? number? x)
              (? variable? x))
          x]))
     [-> Type Type])

Program 3:

#lang typed/racket
(define-type Variable (Refine [var : Symbol] (! var 'λ)))
(define-predicate variable? Variable)
(define-type Type (U Number Variable (Listof Type)))
(ann (lambda (arg)
       (match arg
         [(or (? number? x)
              (? variable? x))
          x]))
     [-> Type Type])

What should have happened?

Print a procedure.

If I change or pattern to 2 different patterns in match, the above codes will work properly.

(match arg
  [(? number? x) x]
  [(? variable? x) x])

If you got an error message, please include it here.

Program 1: Why could x be False type?

Type Checker: type mismatch
  expected: Type
  given: (U False Type)
  in: x

Program 2: Why could x be Symbol type instead of Variable type?

Type Checker: type mismatch
  expected: Type
  given: (U Complex False Symbol)
  in: x

Program 3: The program stucks in an endless loop.

Start by running the three typed/racket programs from the issue under Racket v7.8 and compare their or patterns with the equivalent separate match clauses. Investigate the reported false or widened types and the endless loop; done means all three programs type-check and produce the expected procedure behavior without looping.