This is the settings tab of my Home page:
I’m happy with the Search Result Preview. But what actually shows up on Google does not match this:
It’s been like this for a few months now.
Strangely, the meta description is indeed correct on Bing!
Any idea why the Google meta description is incorrect? 
The forum is has many posts where others had the same or similar questions. Please make sure you search them before posting.
You are making an incorrect assumption that Google should only use what you provide. In search central they clearly describe how they use AI to render the snippet shown to users. You can read about it at Google Search Central (formerly Webmasters) | Web SEO Resources | Google for Developers
