.prop was removed in 3.0. It was reintroduced in 3.2.
see vuejs/core@
1c7d737
| FILTERS | ✔ | Filters removed (this option affects only runtime filter APIs) | [link](https://v3-migration.vuejs.org/breaking-changes/filters.html) |
| COMPILER_IS_ON_ELEMENT | ✔ | `is` usage is now restricted to `<component>` only | [link](https://v3-migration.vuejs.org/breaking-changes/custom-elements-interop.html) |
| COMPILER_V_BIND_SYNC | ✔ | `v-bind.sync` replaced by `v-model` with arguments | [link](https://v3-migration.vuejs.org/breaking-changes/v-model.html) |
-| COMPILER_V_BIND_PROP | ✔ | `v-bind.prop` modifier removed | |
| COMPILER_V_BIND_OBJECT_ORDER | ✔ | `v-bind="object"` is now order sensitive | [link](https://v3-migration.vuejs.org/breaking-changes/v-bind.html) |
| COMPILER_V_ON_NATIVE | ✔ | `v-on.native` modifier removed | [link](https://v3-migration.vuejs.org/breaking-changes/v-on-native-modifier-removed.html) |
| COMPILER_V_FOR_REF | ✔ | `ref` in `v-for` (compiler support) | |