op item create doesnt work in GitHub Actions

When I use op item list or op item get in GitHub Actions, they work as expected. But when I use op item create in GitHub Actions, it doesn't work (the item doesn't get created), and I don't get any error message either. The same command, when run locally, works just fine outside of GitHub Actions. Can anybody advise how to get op item create to work in the context of GitHub Actions?

Note: I'm using the new Service Account beta feature.

And here is how to reproduce the problem on-demand in GitHub Actions:

name: Test 1Password
on:
  # workflow_dispatch allows the action to be kicked off on-demand manually.
  workflow_dispatch:

defaults:
  run:
    shell: bash

jobs:
  add_item:
    runs-on: ubuntu-latest
    steps:
      - name: Check out this repo
        uses: actions/checkout@v3

      - name: Install 1Password CLI
        run: |
          curl -sS -L --output /tmp/1p.zip https://cache.agilebits.com/dist/1P/op2/pkg/v2.10.0-beta.02/op_linux_$(dpkg --print-architecture)_v2.10.0-beta.02.zip
          unzip /tmp/1p.zip op -d /usr/local/bin/
          rm -f /tmp/1p.zip

      - name: Create item in 1Password
        run: |
          set -x

          # This evaluates to `2.10.0-beta.02`, so presumably the CLI is installed and usable
          op --version

          # This also works as expected
          op item list --vault MyCustomVault --format json

          # And if you prepopulate an item called `bar`, this will work as expected too
          op item get bar --vault MyCustomVault --format json

          # But this doesnt create any item, and also doesnt output anything to stderr or stdout
          op item create --vault MyCustomVault --title foo --url "sftp://example.com" --category Login --format json "username=foo" "GitHub_Issue=${{ github.server_url }}/${{ github.repository }}/issues/${{ github.event.issue.number }}" --generate-password
        env:
          OP_SERVICE_ACCOUNT_TOKEN: ${{ secrets.OP_SERVICE_ACCOUNT_TOKEN }}
          OP_DEBUG: "true"

1Password Version: 2.10.0-beta.02
Extension Version: Not Provided
OS Version: Ubuntu
Browser:_ Not Provided