A DESCRIPTION OF THE PROBLEM :
According to https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/time/ZoneId.html#systemDefault(), it should be true, that "If the system default time-zone is changed, then the result of this method will also change."

This buggy (?) behavior was probably introduced with the following optimization:
https://bugs.openjdk.org/browse/JDK-8074002

I think that either implementation or javadoc should be fixed.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Run jshell, invoke ZoneId.systemDefault():
jshell> java.time.ZoneId.systemDefault()
=> Initial/Timezone

Do not close jshell!

2. In parallel, change system time zone:
$ sudo timedatectl set-timezone Other/Timezone

3. Go back to jshell, invoke ZoneId.systemDefault() again:
jshell> java.time.ZoneId.systemDefault()


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
=> Other/Timezone
ACTUAL -
=> Initial/Timezone