Yes, exactly. Problem is in
additionalProperties. It can be tricky and we recommend to stick with
false by default, especially if you control source of data.
For new property you will have to bump version in ADDITION (e.g.
1-0-1) if that new property is optional. Otherwise, if new property is required - this is again MODEL bump (
2-0-0) because all historical data will be invalid against new schema (field is required) and all new data will be invalid against previous schema (previous schema explicitly stated there’s no such property), so they’re backward and forward incompatible.