YAML meta not working

### Is this a hackmd.io issue?

- [x] Yes, the bug happens on https://hackmd.io
- [ ] No. If it's a self-hosted CodiMD instance, please fire up the issue in the repo of CodiMD: https://github.com/hackmdio/codimd

### What's the problem
Adding YAML meta in note didn't work.

#### Current behaviour

add YAML to note

```
---
title: my title
image: https://www.helloworld.image
---
```

Press share note and publish.

Paste a link to social media and the og title, image still not showing.

#### Expected behaviour

It should reflect to YAML.

#### Environment

I use HackMD on:

Macbook m1 pro