通过 finkcdc 同步mysql数据到doris【3.0.4、3.0.5】，报错 fail to apply alter column type event，3.0.3没有问题

ods_tms_taskbill_oi_detail 中bi_name 字段类型是varchar， 默认值是''，如下图：

mysql 数据通过flinkcdc 同步数据，在mysql表结构没有变更的情况下，
doris 3.0.4和3.0.5都报错下面的错误，3.0.3没有问题。

flink cdc 用的是3.4.0

flink-cdc-pipeline-connector-doris-3.2.1.jar

2025-06-10 13:50:35
org.apache.flink.util.FlinkException: Global failure triggered by OperatorCoordinator for 'Transform:Data -> SchemaOperator -> PrePartition' (operator 9899a42c64d67ef3172b7e3be3c1bbb9).
	at org.apache.flink.runtime.operators.coordination.OperatorCoordinatorHolder$LazyInitializedCoordinatorContext.failJob(OperatorCoordinatorHolder.java:651)
	at org.apache.flink.cdc.runtime.operators.schema.common.SchemaRegistry.failJob(SchemaRegistry.java:392)
	at org.apache.flink.cdc.runtime.operators.schema.regular.SchemaCoordinator.lambda$startSchemaChangesEvolve$1(SchemaCoordinator.java:249)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
	at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.base/java.lang.Thread.run(Unknown Source)
Caused by: org.apache.flink.util.FlinkRuntimeException: Failed to apply schema change event.
	... 6 more
Caused by: SchemaEvolveException{applyingEvent=AlterColumnTypeEvent{tableId=ods.ods_tms_taskbill_oi_detail, typeMapping={bi_name=STRING NOT NULL}, oldTypeMapping={bi_name=VARCHAR(255) NOT NULL}}, exceptionMessage='fail to apply alter column type event', cause='org.apache.doris.flink.exception.DorisSchemaChangeException: Failed to schemaChange, response: {"msg":"Error","code":1,"data":"Failed to execute sql: java.sql.SQLException: (conn=6888) errCode = 2, detailMessage = Can not change default value","count":0}'}
	at org.apache.flink.cdc.connectors.doris.sink.DorisMetadataApplier.applyAlterColumnTypeEvent(DorisMetadataApplier.java:297)
	at org.apache.flink.cdc.connectors.doris.sink.DorisMetadataApplier.lambda$applySchemaChange$1(DorisMetadataApplier.java:120)
	at org.apache.flink.cdc.common.event.visitor.SchemaChangeEventVisitor.visit(SchemaChangeEventVisitor.java:52)
	at org.apache.flink.cdc.connectors.doris.sink.DorisMetadataApplier.applySchemaChange(DorisMetadataApplier.java:113)
	at org.apache.flink.cdc.runtime.operators.schema.regular.SchemaCoordinator.applyAndUpdateEvolvedSchemaChange(SchemaCoordinator.java:437)
	at org.apache.flink.cdc.runtime.operators.schema.regular.SchemaCoordinator.applySchemaChange(SchemaCoordinator.java:406)
	at org.apache.flink.cdc.runtime.operators.schema.regular.SchemaCoordinator.lambda$startSchemaChangesEvolve$1(SchemaCoordinator.java:247)
	... 5 more
Caused by: org.apache.doris.flink.exception.DorisSchemaChangeException: Failed to schemaChange, response: {"msg":"Error","code":1,"data":"Failed to execute sql: java.sql.SQLException: (conn=6888) errCode = 2, detailMessage = Can not change default value","count":0}
	at org.apache.doris.flink.sink.schema.SchemaChangeManager.handleSchemaChange(SchemaChangeManager.java:232)
	at org.apache.doris.flink.sink.schema.SchemaChangeManager.execute(SchemaChangeManager.java:273)
	at org.apache.doris.flink.sink.schema.SchemaChangeManager.schemaChange(SchemaChangeManager.java:194)
	at org.apache.doris.flink.sink.schema.SchemaChangeManager.modifyColumnDataType(SchemaChangeManager.java:164)
	at org.apache.flink.cdc.connectors.doris.sink.DorisMetadataApplier.applyAlterColumnTypeEvent(DorisMetadataApplier.java:286)
	... 11 more