I am trying to write some simple TypeScript code to change a conditional formatting rule in an Excel file. To repro my issue:

• Open a blank Excel file
• Enter 1 in A1
• Click “Home”, Conditional formatting”, “New Rule”
• Choose “Format only cells that contain”
• Select “Specific text” in the Format only cells with: drop-down on
  the left
• Select “Containing” in the second drop-down
• Enter 123 in the box.
• OK back to Excel.
• Open Script lab and import the code below and run it
• Click the Run button, the console should state 123, followed by 456.
• Click Conditional formatting, Manager Rules.
• You should see that the contains text rule is unchanged!

What is wrong with this code?

================Script lab code================

name: CheckCF
description: ''
host: EXCEL
api_set: {}
script:
  content: |
    $("#run").on("click", () => tryCatch(run));

    async function run() {
      await Excel.run(async (context) => {
        const sheet = context.workbook.worksheets.getActiveWorksheet();

        let cfRules = sheet.getRange("A1").conditionalFormats;
        let cf = cfRules.getItemAt(0);
        let containsTextCF = cf.textComparisonOrNullObject;
        containsTextCF.load();
        await context.sync();
        console.log(containsTextCF.rule.text);
        containsTextCF.rule.text = "456";
        await context.sync();
        console.log(containsTextCF.rule.text);
      });
    }

    /** Default helper for invoking an action and handling errors. */
    async function tryCatch(callback) {
      try {
        await callback();
      } catch (error) {
        // Note: In a production add-in, you'd want to notify the user through your add-in's UI.
        console.error(error);
      }
    }
  language: typescript
template:
  content: |
    <button id="run" class="ms-Button">
        <span class="ms-Button-label">Run</span>
    </button>
  language: html
style:
  content: |-
    section.samples {
        margin-top: 20px;
    }

    section.samples .ms-Button, section.setup .ms-Button {
        display: block;
        margin-bottom: 5px;
        margin-left: 20px;
        min-width: 80px;
    }
  language: css
libraries: |
  https://appsforoffice.microsoft.com/lib/1/hosted/office.js
  @types/office-js

  [email protected]/dist/css/fabric.min.css
  [email protected]/dist/css/fabric.components.min.css

  [email protected]/client/core.min.js
  @types/core-js

  [email protected]
  @types/[email protected]

================End of Script lab code================