docker buildx not using /etc/hosts

[Placeboy]

I modified the /etc/hosts file to redirect to my private registry for some test work.
Docker login succeed:

$ sudo docker login -u test-user -p xxxxxxxx example.registry.com
WARNING! Using --password via the CLI is insecure. Use --password-stdin.
WARNING! Your password will be stored unencrypted in /root/.docker/config.json.
Configure a credential helper to remove this warning. See
https://docs.docker.com/engine/reference/commandline/login/#credentials-store

Login Succeeded

Docker pull failed as expected because no project named base on my test-version private registry:

$ sudo docker pull example.registry.com/base/tomcat:latest
Error response from daemon: unauthorized: project base not found: project base not found

However, When I built image using:

$ sudo docker buildx build --file Dockerfile --output type=image,name=example.registry.com/docker-test/test-api:gzip,oci-mediatypes=true,compression=gzip,force-compression=true,push=true .

It successfully pulled the image example.registry.com/base/tomcat:latest, which only exists on the released registry(not my test version), but it failed to push image, reporting error like this:

=> ERROR exporting to image                                                                                                                                                                                     11.5s
 => => exporting layers                                                                                                                                                                                           7.6s
 => => exporting manifest sha256:598cb1fffaa7be8d623139149fce7c4f54eeaa911714f47441bb7eab60f77d44                                                                                                                 0.1s
 => => exporting config sha256:a476373d59572acddecb96d20b204cbec8f7bed1ce3939cbd31225bcdfb83aa8                                                                                                                   0.2s
 => => pushing layers                                                                                                                                                                                             3.5s
------
 > exporting to image:
------
error: failed to solve: rpc error: code = Unknown desc = unexpected response: 401 Unauthorized

So I guess that docker login worked, but /etc/hosts did not work.

Additional Information

docker version:

Client:
 Version:           20.10.1
 API version:       1.41
 Go version:        go1.13.15
 Git commit:        de59dc9599
 Built:             Wed Aug 11 09:32:55 2021
 OS/Arch:           linux/amd64
 Context:           default
 Experimental:      true

Server:
 Engine:
  Version:          library-import
  API version:      1.41 (minimum version 1.12)
  Go version:       go1.20
  Git commit:       library-import
  Built:            library-import
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.6.5
  GitCommit:        6157bba8876eae99d8afd9ab40ff29bf7d1fb76a.m
 runc:
  Version:          1.1.2
  GitCommit:        dc2d880
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

Somebody could help me?