Why does a look like s on Twitch?

In Twitch Chat, an a always looks like an s for me. I can't explain why. In the picture you can see it, the first is an a and the second is an s. Does anyone know why?

The first looks like an a the second like a document lol

It actually says bynashii but it looks like bynaahii

Will probably be due to your resolution and the font used by Twitch. I have the problem e.g. Not with WQHD - but I haven't noticed it yet with FullHD either

But I've only had it for about a month