Please help me, how do I fix this is issue .
You can have multiple versions of Java installed on the same machine, and unfortunately, it can be a bit complicated guaranteeing which version runs. Here you’re running java under systemd, so the path used for java may override the “default” install. Please take a look at what you see under journalctl -u jenkins to see what’s actually installed at /usr/bin/java, which if you look at the output for systemctl status jenkins, is the java getting run. It might not be the version you just installed. If so, the solution may well be to edit the unit file for systemd, using the exact path you want for Java 17.