I have the same problem. I setted manually the directory of libreoffice program classes.
The Jabref start search for the synchrony and finish with the error of Autodetection failed:
com.sun.star.comp.helper.BootstrapException
at org.jabref@5.2.233/org.jabref.gui.openoffice.Bootstrap.bootstrap(Unknown Source)
at org.jabref@5.2.233/org.jabref.gui.openoffice.Bootstrap.bootstrap(Unknown Source)
at org.jabref@5.2.233/org.jabref.gui.openoffice.OOBibBase.simpleBootstrap(Unknown Source)
at org.jabref@5.2.233/org.jabref.gui.openoffice.OOBibBase.<init>(Unknown Source)
at org.jabref@5.2.233/org.jabref.gui.openoffice.OpenOfficePanel.createBibBase(Unknown Source)
at org.jabref@5.2.233/org.jabref.gui.openoffice.OpenOfficePanel$2.call(Unknown Source)
at org.jabref@5.2.233/org.jabref.gui.openoffice.OpenOfficePanel$2.call(Unknown Source)
at org.jabref.merged.module@5.2.233/javafx.concurrent.Task$TaskCallable.call(Unknown Source)
at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.base/java.lang.Thread.run(Unknown Source)