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React-Redux most recently POSTed object is always undefined until I refresh

So I'm working with react and redux to make a simple blog app where you fill out a form and onSubmit that data is added to a grid of other posts. However, when I use the useSelector() method to gather the state, the most recently POST'd object is always undefined, even though it properly makes it through redux. Here's the flow:

From Form:

const handleSubmit = (e) => {
        e.preventDefault()
        console.log("FORM DATA:")
        console.log(postData);
        dispatch(createPost(postData));
    }

Here's the action dispatched:

export const createPost = (post) => async (dispatch) => {
    try 
    {
        const data = await api.createPost(post);
        console.log("ACTION DATA:");
        console.log(data.data);
        dispatch({ type: "CREATE", payload: data.data});
    } 
    catch (error) 
    {
        console.log(error.message);
    }
}

Here is the reducer associated with the action, with the case being 'CREATE':

export default (posts = [], action) => {
    switch (action.type) {
        case "FETCH_ALL":
            return action.payload;
        case "CREATE":
            console.log("REDUCER DATA:")
            console.log(action.payload);
            return [...posts, action.paylaod];
        default:
            return posts;
    }
}

Here's my component that dynamically renders the posts:

const Posts = () => {
    const classes = useStyles();
    const getState = useSelector((state) => {
        return state;
    })
    const posts = getState.posts;
    console.log(posts);
    return (
        !posts.length ? <CircularProgress /> : (
          <Grid className={classes.container} container alignItems="stretch" spacing={3}>
            {posts.map((post, index) => (
              <Grid key={index} item xs={12} sm={6} md={6}>
                <Post post={post}/>
              </Grid>
            ))}
          </Grid>
        )
      );
    
}

Above is where I first noticed the error. When I submit the form, the console log just after the useSelector() methods returns the array of post objects, however the one that I just added is ALWAYS undefined. This means I run into an error trying to render a post because the object can't be read as it's undefined:

const Post = ({ post }) => {
    const classes = useStyles();

    
    return (
        <Card className={classes.card}>
            <CardMedia className={classes.media} image={'https://user-images.githubusercontent.com/194400/49531010-48dad180-f8b1-11e8-8d89-1e61320e1d82.png'} title={post.title}/>
            <div className={classes.overlay}>
                <Typography variant='h6'>{post.creator}</Typography>
                <Typography variant='body2'>{moment(post.createdAt).fromNow()}</Typography>
            </div>
            <div className={classes.overlay2}>
                <Button style= size="small" onClick={() => {}}>
                    <MoreHorizIcon fontSize="medium"/>
                </Button>
            </div>
            <div className={classes.details}>
                <Typography variant="body2" color="textSecondary">{post.tags.map((tag) => `#${tag} `)}</Typography>
            </div>
            <Typography className={classes.title} gutterBottom variant="h5" component="h2">{post.title}</Typography>
            <CardContent>
                <Typography variant="body2" color="textSecondary" component="p">{post.message}</Typography>
            </CardContent>
            
        </Card>
     );
}

I immediately run into an issue here trying to read post.title, post.message, etc... as it's all undefined. The only way I've managed to get this to work is to remove e.preventDefault() from the form submit, which works but I'd rather have it all render without having to refresh. What am I missing here? And why would the refresh have any effect on this?

console.log of state after I submit the form:

(10) [{…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, undefined]
0: {_id: '61cd4ebc0a9d0366a8b59fda', title: 'Disney', message: 'message', creator: 'Logan', tags: Array(1), …}
1: {_id: '61cdf29e0a9d0366a8b5a016', title: 'San Diego', message: 'with cousins', creator: 'Logan', tags: Array(1), …}
2: {_id: '61cdf5e00a9d0366a8b5a03f', title: '', message: '', creator: '', tags: Array(1), …}
3: {_id: '61cdf6190a9d0366a8b5a043', title: '', message: '', creator: '', tags: Array(1), …}
4: {_id: '61cdf7e50a9d0366a8b5a047', title: 'll', message: 'llll', creator: 'l', tags: Array(1), …}
5: {_id: '61cdfea1c6f7be0a79b7320f', title: '', message: '', creator: '', tags: Array(1), …}
6: {_id: '61cdfec1c6f7be0a79b73212', title: '', message: '', creator: '', tags: Array(1), …}
7: {_id: '61cdff8ac6f7be0a79b73216', title: '', message: '', creator: '', tags: Array(1), …}
8: {_id: '61cdffc3c6f7be0a79b7321b', title: '', message: '', creator: '', tags: Array(1), …}
9: undefined
length: 10
[[Prototype]]: Array(0)

And after a refresh:

(10) [{…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}]
0: {_id: '61cd4ebc0a9d0366a8b59fda', title: 'Disney', message: 'message', creator: 'Logan', tags: Array(1), …}
1: {_id: '61cdf29e0a9d0366a8b5a016', title: 'San Diego', message: 'with cousins', creator: 'Logan', tags: Array(1), …}
2: {_id: '61cdf5e00a9d0366a8b5a03f', title: '', message: '', creator: '', tags: Array(1), …}
3: {_id: '61cdf6190a9d0366a8b5a043', title: '', message: '', creator: '', tags: Array(1), …}
4: {_id: '61cdf7e50a9d0366a8b5a047', title: 'll', message: 'llll', creator: 'l', tags: Array(1), …}
5: {_id: '61cdfea1c6f7be0a79b7320f', title: '', message: '', creator: '', tags: Array(1), …}
6: {_id: '61cdfec1c6f7be0a79b73212', title: '', message: '', creator: '', tags: Array(1), …}
7: {_id: '61cdff8ac6f7be0a79b73216', title: '', message: '', creator: '', tags: Array(1), …}
8: {_id: '61cdffc3c6f7be0a79b7321b', title: '', message: '', creator: '', tags: Array(1), …}
9: {_id: '61ce01d5c6f7be0a79b7321e', title: '', message: '', creator: '', tags: Array(1), …}
length: 10
[[Prototype]]: Array(0)
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