We installed Wacom driver 6.3.43-3 onto a Mac OS 10.15 computer that has a PTH-451 connected.
Both Pen and Touch input from the Wacom seem to be working. One thing we had to do was to adjust the Cursor Behavior setting in the Kyma Wacom Preferences to be “Do not click, but control cursor” (the middle option).
Perhaps the MacOS Security and Privacy Settings are preventing Kyma from accessing the pen. These should have been set for you automatically the first time you used either Kyma or the Wacom Tablet.
Please open the System Preferences, select Security & Privacy, and click the Privacy tab. Scroll down to Accessibility and make sure that both Kyma and com.wacom.IOManager have check marks next to them. Then select the next item, Input Monitoring, and make sure that WacomTabletDriver is checked there. Next, skip down a couple of rows to Automation and make sure that the entry for TabletDriver (under the Kyma 7+ entry) is checked.