Are both species currently available/active on iNat? If so, it sounds like you can just ID the misidentified ones as the correct species, preferably providing a comment explaining the ID.
If the common name is used for both species, this is can definitely be an issue causing misID’s, but if the common name/s is/are used this way outside of iNat, then the usage on iNat will reflect that.
The common names can be added for different places and set for specific locations. See this thread for some info:
https://forum.inaturalist.org/t/fixing-incorrect-uncommon-common-names/5739
You can also check the curator section on naming for some info:
https://www.inaturalist.org/pages/curator+guide#names