Block validation failed in WordPress 6.4.2, but it works on 6.0.0?

Question

attributes: {
    tabs: {
      type: 'array',
      default: [
        { tabLabel: 'Tab 1', tabContent: 'Content for Tab 1' }
      ],
    },   }, edit: ({ attributes, setAttributes }) => {
    const { tabs } = attributes;
    const updateTabContent = (value, tabIndex) => {
      const updatedTabs = [...tabs];
      updatedTabs[tabIndex].tabContent = value;
      setAttributes({ tabs: updatedTabs });
    };
    return (
      <div className="my-custom-block">
        {tabs.map((tab, tabIndex) => (
          <div key={tabIndex}>
            <RichText
              tagName="h6"
              value={tab.tabLabel}
              onChange={(value) => updateTabLabel(value, tabIndex)}
              placeholder="Tab Label..."
            />
          </div>
        ))}
      </div>
    );   }, save: ({ attributes }) => {
    const { tabs } = attributes;
    return (
      <div className="my-custom-block">
        {tabs.map((tab, tabIndex) => (
          <div key={tabIndex}>
            <h6>{tab.tabLabel}</h6>
            <div>{tab.tabContent}</div>
          </div>
        ))}
      </div>
    );   },

This custom block is triggering an error under WordPress 6.4.2 but if I use WordPress 6.0.0 then it works fine.

This is what I'm seeing on the console:

Block validation: Block validation failed for blogee-accordion-block/blogee-accordion

Content generated by save function: <div class="wp-block-blogee-accordion-block-blogee-accordion"></div>

Content retrieved from post body: <div class="wp-block-blogee-accordion-block-blogee-accordion"><div><p>Tab</p></div><div><p>Tab 2</p></div></div>