Jmeter test interface of PostgreSql, but often happens "idle in transaction" - postgresql

Question

I use Jmeter test the springboot system with druid pool, there are almost 50 interfaces need to be tested. When tested a half (Serial execution), the Jmeter was blocked, then I use sql
select *
from pg_stat_activity
where pid in (select pid
from pg_locks l
join pg_class t on l.relation = t.oid and t.relkind = 'r' );
found that a query sql state is "idle in transaction", and a update sql wait_event_type is "Lock", wait_event is "transactionid".
And I also found if cancel the DataSourceTransactionManager config, run Jmeter OK, there won't happen "idle in transaction". But If config DataSourceTransactionManager, run Jmeter always happend "idle in transaction", whatever there's #Transactional annotation on method
How to avoid "idle in transaction" in this springboot system?
The TransactionManager config like this:
<bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager" primary="true">
<property name="dataSource" ref="wasDataSource"/>
</bean>
The druid config like this:
<property name="maxActive" value="100"/>
<property name="initialSize" value="10"/>
<property name="minIdle" value="10"/>
<property name="maxWait" value="60000"/>
<property name="timeBetweenEvictionRunsMillis" value="60000"/>
<property name="minEvictableIdleTimeMillis" value="250000"/>
<property name="maxEvictableIdleTimeMillis" value="300000"/>
<property name="validationQuery" value="select 1"/>
<property name="testWhileIdle" value="true"/>
<property name="testOnBorrow" value="false"/>
<property name="testOnReturn" value="false"/>
<property name="poolPreparedStatements" value="true"/>
<property name="maxPoolPreparedStatementPerConnectionSize" value="20"/>
The Postgres version is 12.6, springboot is 2.6.6, spring is 5.3.19