I have not been "kicked-out" yet ............ but I wonder if it is a location/browser problem. I am using chrome without any interruption.
The issue of not being able to access the site (i.e., freemathhelp server blocking my IP address) has not been confined to any one location, browser, device or network -- over the past 15 years or so.
It's happened using Samsung's browser, Apple's browser, Chrome, Firefox, Internet Explorer (and, maybe, Microsoft Edge).
It's happened on dozens of networks and devices across five states.
The issue seems to come in waves. Until recently, I can't remember being blocked for two or three years. At one point, Ted had discovered a bug in his security software (attempting to post a particular character string had been interpreted by the Apache software as an attack).
I vaguely remember it all started after switching from PHP to v-Bulletin, and it's been a regular pain in the neck ever since.