Test build failure

Hello
I have a java project with gradle build.

I want to build with Java 8. My code used packages removed in java 11, for example javax.xml.bind.JAXBContext

So , in my build.gradle, I have

    java {
        sourceCompatibility = JavaVersion.VERSION_1_8
        targetCompatibility = JavaVersion.VERSION_1_8
    }

And I can run gradle tasks build/check/test using the vscode gradle side bar item without issues.

But when I try to launch a test using Test runner, the gradle build fails with "error: package javax.xml.bind does not exist"
So it seems to build with Java 11!
So why? Does test runner uses another gradle version (where java sourceCompatibility/targetCompatibility is not supported)?
Does a workaround exists?
I checked also Command -> Configure java runtime , and I have Java 1.8 configured too.

Environment

• Operating System: VScode is running on Windows 10 with a remote-ssh to a Linux workstation
• JDK version: 1.8
• Visual Studio Code version: 1.85.2
• Java extension version: 0.25.15

Inizia dalle impostazioni di compatibilità Java in build.gradle e confronta la build della barra laterale di Gradle con l’invocazione di Test runner nella configurazione remote-SSH segnalata. Controlla il runtime Java configurato e determina perché il percorso di test non riesce a risolvere javax.xml.bind; il lavoro è completato quando la discrepanza è stata riprodotta e viene identificata una correzione documentata o verificata.