React-Redux onClick setState (markdown project)

Hi everyone!!

I’ve been working on the fcc Markdown previewer project as my first React-Redux project ever.
I would say I’ve finished it, but there is still a “bug” that I can’t seem to find:
When you maximize the Preview window you should be able to “shrink it back” clicking again on the header icon, but for some reason it takes two clicks to do so.
Editor window is working fine and I can’t get the reason why they differ.

I still don’t quite get how this React-Redux thing works and I might be doing a lot of things that shouldn’t be done. Trying to debug I found for example that Editor and Preview inner states don’t efectively change after I set them on handleToggler… still they change eventually but I don’t know when.

I would really appreciate if anyone could check my code and tell me all the things I did wrong :sweat_smile:
By the way, I’m struggling with myself since I’ve been taught not to repeat code and use ifs and cases and my code is all about it right now, but I would love to understand what I’m doing first.

Here’s the link to my project: FCC Markdown Previewer

Moving this post to the “help” section,

Can you put a link with your code or codepen example where we can inspect the code live?
Why would you use Redux? what state do you even have to store in Markdown Previewer?
Do you know what Redux is for?

Shift-Ctrl-I shows you what you were asking, but if you find codepen more comfortable, I copy-pasted it here
On code pen
Redux was meant to share state between components since my components are sibilings (no child/parent relationship, suggestion found on stackoverflow )