I cannot get into chat using Microsoft Edge browser No trouble with chrome or Firefox.
I normally use Chrome to access chat room, but have tried on Edge and had no problems getting into the chat room.
My system is Windows 10 and Edge latest build which is 42.17134.1.0 released April 2018.
To check which version you have go to settings and scroll down to 'About this app'
I have block pop ups - off and allow cookies on though it also worked with don't allow cookies.
Sorry cant help more other than suggest you may need to load the latest version of Edge