I tried to set offset 3 and 0, all works fine with statistics with REST setup for now. However, the DAS wso2carbon.log keeps throwing the following error messages:
If you have installed any car files, you may need to update the port of receiver URL in scripts inside them, to match with your offset.
What I did is to remove port 7711 from data receiver config in apim admin-dashabord/Analytics. It is now only list tcp://localhost:7611 . That seems to fix it, but don't know why it did not respond at 7711 as it is actually configured in DAS conf/data-bridge/data-bridge-config.xml.