The public_transport=stop_position tag shouldn't be added to the bus route relation as it will reporting on the OSM Inspector as an Unknown role in a relation.
Please see osm.wiki/Buses#Adding_bus_stops_to_the_relation

Transperth's Spatial Data tells who's operating with those bus routes around areas in Perth and its regional areas.
https://www.transperth.wa.gov.au/About/Spatial-Data-Access

okay got that, as the newly built road is very close to the Railway Parade intersection. :)

Looks like the road next to Bayswater Station is connected directly to Railway Parade rather than Rose Avenue by survey outcome.

Just wondering is there a way to tagging with the CAT ID number from the CAT services in Perth area (I've used "ref:AU-WA:PerthCAT" as an example), if it's okay I can do the same for Joondalup and Fremantle area as well.

When attempting to split up the road segments, it needs to take caution which node to be split up to avoiding the route to be invalid.