Are you trying to do so from Firefox / a reddit app? This is fairly normal and the general conspiracy theory is that it's an erroneous error to get you to download the Twitter app once and for all.
Bone stock phone, nothing notable about it or the browser. Doesn't happen on my Windows or Linux desktops.
I too think it is done intentionally to get users to install the app. I can't think of a reason this is a simple bug. But the again... Hanlon's razor.
Chrome does not respect user privacy and is designed to not support add-ons as it will hurt Google's core advertising business.