Just a quick update: eventually I resolved the issue by creating a virtual switch in Homey (remember to switch on the virtual device option in Homey’s experimental settings section).
A quick creation of a ‘on’ and ‘off’ flow switching on or off my lights based on the status change of the virtual switch, and a google home device sync later and it works as intended.
It’s a bit if a workaround, but at least it works. 
