If I select server with red dot and try to connect after a while it will show message that I have a mod selected that is not supported, but then server browser gets crippled and updates very slowly. Additionally this cripples my entire home connection, I suspect it does something to the wifi router too because all my other wifi devices get crippled as well. This lasts for a few minutes.

Also when this is happening trying to connect to red X server may just say connection lost on the first try and only on second try say bad version.