JDBC connector wrongly uses default value when value is NULL on optional fields

Hello~, I have encountered a problem with the default value of the field, The source table is not consistent with the target table , for example:

 

This is a piece of json data from id=1 
{
"schema": {
"type": "struct",
"fields": [
{
"type": "struct",
"fields": [

{ "type": "int32", "optional": false, "field": "id" }

,

{ "type": "string", "optional": true, "default": "zhangsan", "field": "name" }

,

{ "type": "int32", "optional": true, "field": "age" }

,

{ "type": "string", "optional": true, "field": "timestamp" }

,

{ "type": "string", "optional": true, "default": "1", "field": "char" }

,

{ "type": "int32", "optional": true, "default": 100, "field": "int" }

],
"optional": true,
"name": "Mysql_140.wangzc_test.a_wzc_default_value.Value",
"field": "before"
},
{
"type": "struct",
"fields": [

{ "type": "int32", "optional": false, "field": "id" }

,

{ "type": "string", "optional": true, "default": "zhangsan", "field": "name" }

,

{ "type": "int32", "optional": true, "field": "age" }

,

{ "type": "string", "optional": true, "field": "timestamp" }

,

{ "type": "string", "optional": true, "default": "1", "field": "char" }

,

{ "type": "int32", "optional": true, "default": 100, "field": "int" }

],
"optional": true,
"name": "Mysql_140.wangzc_test.a_wzc_default_value.Value",
"field": "after"
},
{
"type": "struct",
"fields": [

{ "type": "string", "optional": false, "field": "version" }

,

{ "type": "string", "optional": false, "field": "connector" }

,

{ "type": "string", "optional": false, "field": "name" }

,

{ "type": "int64", "optional": false, "field": "ts_ms" }

,
{
"type": "string",
"optional": true,
"name": "io.debezium.data.Enum",
"version": 1,
"parameters":

{ "allowed": "true,last,false,incremental" }

,
"default": "false",
"field": "snapshot"
},

{ "type": "string", "optional": false, "field": "db" }

,

{ "type": "string", "optional": true, "field": "sequence" }

,

{ "type": "string", "optional": true, "field": "table" }

,

{ "type": "int64", "optional": false, "field": "server_id" }

,

{ "type": "string", "optional": true, "field": "gtid" }

,

{ "type": "string", "optional": false, "field": "file" }

,

{ "type": "int64", "optional": false, "field": "pos" }

,

{ "type": "int32", "optional": false, "field": "row" }

,

{ "type": "int64", "optional": true, "field": "thread" }

,

{ "type": "string", "optional": true, "field": "query" }

],
"optional": false,
"name": "io.debezium.connector.mysql.Source",
"field": "source"
},

{ "type": "string", "optional": false, "field": "op" }

,

{ "type": "int64", "optional": true, "field": "ts_ms" }

,
{
"type": "struct",
"fields": [

{ "type": "string", "optional": false, "field": "id" }

,

{ "type": "int64", "optional": false, "field": "total_order" }

,

{ "type": "int64", "optional": false, "field": "data_collection_order" }

],
"optional": true,
"name": "event.block",
"version": 1,
"field": "transaction"
}
],
"optional": false,
"name": "Mysql_140.wangzc_test.a_wzc_default_value.Envelope",
"version": 1
},
"payload": {
"before": null,
"after":

{ "id": 1, "name": null, "age": 18, "timestamp": null, "char": null, "int": null }

,
"source":

{ "version": "2.4.0.Final", "connector": "mysql", "name": "Mysql_140", "ts_ms": 1701065788000, "snapshot": "first", "db": "wangzc_test", "sequence": null, "table": "a_wzc_default_value", "server_id": 0, "gtid": null, "file": "master.000018", "pos": 883521573, "row": 0, "thread": null, "query": null }

,
"op": "r",
"ts_ms": 1701065788073,
"transaction": null
}
}