Entering Characters Replaces Others

Hi,
After the issues with the website open.appacademy.io a few hours ago which lasted about 30 min, I’ve been having issues entering characters, which now behaves like in CMD, if I put cursor before the character and start typing it replaces the next one. Wasn’t like this before. This is in Intro chapter, Ruby exercises.

If it can be changed please do, it’s not behaving like a normal editor would. If it’s possible that it’s on my end please tell me how to fix it.

Thanks,
Alek

Edit: Ok, looks like it was on my end. I refreshed again and now seems to work.