Ad-hoc snapshot does not effect sometime after sending a signal to Kafka signal table

{
  "connector.class": "io.debezium.connector.mysql.MySqlConnector",
  "tasks.max": "1",
  "database.hostname": "sr-test-mysql-school-master-1.xxx.com",
  "database.port": "3306",
  "database.user": "xxx",
  "database.password": "xxx",
  "database.connectionTimeZone": "Asia/Shanghai",
  "database.include.list": "seewo_school,seewo_school_teaching_plan,seewo_time_capsule",
  "database.server.name": "debezium.sync.sr_test_mysql_school_master_1_xxx_3306",
  "database.history.kafka.bootstrap.servers": "xxx",
  "database.history.kafka.topic": "debezium.sync.dbhistory.sr_test_mysql_school_master_1_xxx_3306",
  "table.include.list": "seewo_school.school,seewo_school_teaching_plan.t_teacher_teaching_plan_info,seewo_time_capsule.t_time_capsule",
  "snapshot.locking.mode": "minimal",
  "snapshot.mode": "initial",
  "read.only": "true",
  "topic.creation.enable": "true",
  "topic.creation.default.partitions": "1",
  "topic.creation.default.replication.factor": "3",
  "topic.creation.default.cleanup.policy": "compact",
  "topic.creation.default.compression.type": "snappy",
  "topic.creation.default.min.compaction.lag.ms": "86400000",
  "signal.kafka.topic": "debezium.sync.sr_test_mysql_school_master_1_xxx_3306-signal",
  "signal.kafka.bootstrap.servers": "xxx",
  "decimal.handling.mode": "double",
  "time.precision.mode": "connect",
  "binary.handling.mode": "bytes",
  "tombstones.on.delete": "true",
  "include.schema.changes": "true",
  "max.queue.size": "8192",
  "max.batch.size": "2048",
  "producer.override.acks": 1,
  "producer.override.compression.type": "snappy",
  "converters": "customTimestampConverter",
  "customTimestampConverter.type": "io.debezium.converter.TimestampConverter",
  "customTimestampConverter.type.namelist": "year,date,time,datetime,timestamp",
  "value.converter": "org.apache.kafka.connect.json.JsonConverter",
  "key.converter": "org.apache.kafka.connect.json.JsonConverter"
}