Okay what I did now, in all modules I configured as follows:
src/main/resources:
I use logging configuration in application.properies like logging.level.* as described in the question.
src/test/resources:
I use logback-test.xml like:
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<include resource="org/springframework/boot/logging/logback/base.xml" />
<logger name="*.myapp" level="error" />
<logger name="org.springframework.core " level="error" />
<logger name="org.springframework.beans" level="error" />
<logger name="org.springframework.context" level="error" />
<logger name="org.springframework.transaction" level="error" />
<logger name="org.springframework.web" level="error" />
<logger name="org.springframework.test" level="error" />
<logger name="org.hibernate" level="error" />
</configuration>
But I still don’t understand, why in few modules I could use application.properties, but in another module it ignores … But for now it works for me as it is.
But maybe few hints with background knowledge are still welcome.
I dont mark my answer as solution, cos it still feels like a workaround.