createmeta field info about is required isn't correct

[jerry]

i get the info by the url :http://*/rest/api/latest/issue/createmeta?projectKeys=*&issuetypeNames=* 

response is :

"customfield_10800": {

"required": false,

"schema": {

"type": "option",

"custom": "com.atlassian.jira.plugin.system.customfieldtypes:select",

"customId": 10800

},

"name": "问题严重性",

"hasDefaultValue": false,

"operations": [

"set"

],

customfield_10800 isn't required 

but when i create issue without  "customfield_10800 ", request is :

{

"fields": {

"project":

{

"key": "SELLSERVIC"

},

"summary": "test",

"description": "Creating an issue while setting custom field values",

"issuetype": {

"name": "售后预处理"

}

}

}

i can't create issue  response is :

{

"errorMessages": [],

"errors": {

"customfield_10800": "请选择“...""

}

}