@wsenf:
The vera update caused reboot / luup restart. That’s why the HUE devices disappeared not immedialty after the HUE hub update but after the vera update. I guess the code which syncs the devices with the hub and VERA will run only during the initialization / boot process.
I modified the HUE plug-in lua code by replacing the manufacturer name from “Signify…” to “Philips”.
I imported an backup that still contains all my HUE devices and replaced the lua file with my modificated code. Now it continues to work fine.