It seems that the older version (2.3.0.201803141709) of the binding is still there and it is causing a conflict (?)
Check in OH2 console the list of bundles:
bundle:list -s |grep chromecast
Ps: Note that S1276 has an issue with the rules: [SOLVED] WARNING - latest SNAPSHOT 1276. This shouldn’t be related to your case but you may want to downgrade to S1275 just in case.
Thanks for the hint. I forgot that quite a while ago i was helping test the chromecast binding and still had that in my addons folder. uninstalled, deleted the jar and installed again all good and working