Sure, feel free to send a direct personal message, if you would like to share the account details.
The following is my account information, please help verify whether the normal release.
Yes, your ES is perfectly stable, and I was able to publish an experience. From what I understand, you are using username as "pioneer" which is not the one provided in the "Welcome Email". I would suggest to follow the below:
Open Thingworx Studio:
User name = email@example.com
Password = aRHQK6nGwm6 (this is your password, as provided in the welcome email)
It will show the URL as Valid - Technically, it represents everything is IN-PLACE.
Pardon me for repeating again!!, but the above procedure works well from my side. If this doesn't work, there isn't a resolution except for your Private network (that is blocking URLs), for which I would recommend to contact Your Network Admin.
Just an FYI, By saying direct message, I was directing to make use of a message to a specific user. Please be cautious while sharing your username/password.