Style Autoprefixer broken for `display: flex`

**Steps to reproduce the behavior:**
```
({
...base,
display: 'flex',
})
}}
/>
```

_TLDR;_
To fix, add space after flex to fix the issue but no prefix is added.
i.e `display: 'flex '`

_Environment_:
npm@6.145
node@v13.14.0

**Expected style behavior:**
```
display: -webkit-box;
display: -ms-flexbox;
display: flex;
```
_Or_
```
display: flex;
```

**Actual style behavior:**
```
display: -webkit-box,-moz-box,-ms-flexbox,-webkit-flex,flex;
```
_**invalid style**_
###