Concept2 and Garmin Connect duplicate entries

I have a Garmin Descent Mk1. I use this to transmit HR data to the Concept2 PM5 monitor on our indoor rower. I do this by using the 'row indoor' App and have the HR data transmit while using it. The problem is that at the end of a workout I have 2 entries - one from Concept2 which syncs to Garmin Connect and one from my watch..

Is there anyway either to prevent the duplicates in the first place, or merge the duplicate entries?

I realise I *could* not use the watch, but then I wouldn't have the benefit of the HR data on the rowing machine and in the log entries

Any suggestions?
Thank you