Got code = 2 error response when using IOS device but pc and android devices works well

Versions:
- "grpc": "^1.24.0",
- "grpc-web": "^1.2.1"
- "go-micro/v2": " v2.9.1"

When I make a request via the iPhone device, I will get an error on both Safari and Chrome browser.
`
{"code":2,"message":"Http response at 400 or 500 level","metadata":{}}
`

The Envoy access log is listed below.
`
"start_time":"2020-10-31T04:31:07.410Z"
"method":"POST"
"request_id":"85e90781-b396-4452-ab9f-93ae48d71c5c"
"x_forwarded_for":"-"
"bytes_sent":"352"
"upstream_cluster":"auth_interface"
"downstream_remote_address":"218.215.12.209:49663"
"path":"/rm.service.user.UserService/Auth"
"protocol":"HTTP/2"
"upstream_service_time":"93"
"duration":"94"
"upstream_transport_failure_reason":"-"
"response_code":"200"
"response_flags":"-"
"requested_server_name":"-"
"bytes_received":"56"
"istio_policy_status":"-"
"request_accept":"application/grpc-web-text"
"route_name":"-"
"user_agent":"Mozilla/5.0 (iPhone; CPU iPhone OS 13_6 like Mac OS X) AppleWebKit/605.1.15 (KHTML
like Gecko) CriOS/86.0.4240.93 Mobile/15E148 Safari/604.1"
`