Changelog and .release-please-manifest.json are not updated

We are trying to introduce release-please to our project. It's a gradle project (java). We are using generic updater using extra-files.

Our setup is as below:
`.release-please-manifest.json` at the root of the project
```json
{
".": "1.0.0"
}
```
`release-please-config.json` at the root of the project
```json
{
"packages": {
".": {
"changelog-path": "CHANGELOG.md",
"release-type": "java",
"bump-minor-pre-major": false,
"bump-patch-for-minor-pre-major": false,
"draft": false,
"prerelease": false,
"include-component-in-tag": false,
"include-v-in-tag": false,
"extra-files": [ "gradle.properties" ]
}
},
"$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json"
}
```

`gradle.properties`
```text
# {x-release-please-start-version}
version=1.0.0
# {x-release-please-end-version}
```

`CHANGELOG.md` at root directory
```md
# Changelog

## [1.0.0](link-to-pr)
* feat-1
```

While I am trying with CLI in a jenkins pipeline (as below)
`release-please release-pr \
--token=${GITHUB_TOKEN} \
--repo-url=my-repo.git \
--target-branch=target-branch --debug`

- target-branch has a feat commit after release 1.0.0.

PR contains only below changes:
`gradle.properties`
```text
# {x-release-please-start-version}
version=1.1.0-SNAPSHOT
# {x-release-please-end-version}
```
Which is correct but `CHANGELOG.md` or `.release-please-manifest.json` are not updated. What are we doing wrong here?