I cannot add and delete my cloud functions

I tried to add my function in the Seoul Region.

exports.iowa = functions.region("us-central1").https.onRequest((req, res) => {
  return cors()(req, res, () => {
    res.send("Hi from Iowa, USA")
  })
})

exports.london = functions
  .region("europe-west2")
  .https.onRequest((req, res) => {
    return cors()(req, res, () => {
      res.send("Hi from London, UK")
    })
  })

exports.hongkong = functions
  .region("asia-east2")
  .https.onRequest((req, res) => {
    return cors()(req, res, () => {
      res.send("Hi from Hongkong, Hongkong")
    })
  })

exports.seoul = functions
  .region("asia-northeast3")
  .https.onRequest((req, res) => {
    return cors()(req, res, () => {
      res.send("Hi from Seoul, Korea")
    })
  })

But I faced this error.

functions: failed to create function seoul HTTP Error: 403, Permission denied on 'locations/asia-northeast3' (or it may not exist).

I cannot see that function in my cloud functions console and firebase console too. But the weirdest thing is this function is really working now.

And I cannot delete that function with cli command

firebase-test> firebase functions:delete seoul Error: The specified filters do not match any existing functions in project

How can I add or delete that function with that Tier 2 region (asia-northeast3)