Wildfly doesnt respect source-vm and target-vm options

I am using wildfly with jdk 17.

I want to compile some old jsp pages with level 17.

I tried with the following

<jsp-config development="true" check-interval="1" modification-test-interval="1" recompile-on-fail="true" source-vm="17" target-vm="17"/>   

and it compiles with level 51.

I tried with the following

<jsp-config development="true" check-interval="1" modification-test-interval="1" recompile-on-fail="true" source-vm="1.8" target-vm="1.8"/>

and it correctly compiles with level 52.

Is this an error in parsing? How can jsp pages be compiled with source-vm >= 15?

I need to use text blocks.

Thank you