Create PR from issue doesn't work - there's not anything to compare


Using this specific worfkflow
```yaml
name: Claude PR Assistant

on:
issue_comment:
types: [created]
pull_request_review_comment:
types: [created]
issues:
types: [opened, assigned]
pull_request_review:
types: [submitted]

jobs:
claude-code-action:
if: |
(github.event_name == 'issue_comment' && contains(github.event.comment.body, '@claude')) ||
(github.event_name == 'pull_request_review_comment' && contains(github.event.comment.body, '@claude')) ||
(github.event_name == 'pull_request_review' && contains(github.event.review.body, '@claude')) ||
(github.event_name == 'issues' && contains(github.event.issue.body, '@claude'))
runs-on: ubuntu-latest
permissions:
contents: read
pull-requests: read
issues: read
id-token: write
steps:
- name: Checkout repository
uses: actions/checkout@v4
with:
fetch-depth: 1

- name: Run Claude PR Action
uses: anthropics/claude-code-action@beta
with:
anthropic_api_key: ${{ secrets.CLAUDE_API_KEY }}
timeout_minutes: "60"
```

I can see reasoning, and what's exactly to change there, but PR part fails
I've got PR url on top, job is done and no link at the bottom

Using official app for an installation