|Nothing wrong on your end.|
You need to call your IT department and present them with the log.
It looks to me that you made the connection successfully.
It's what follows. The vpn server was the next step. Only folks that can fix this is your IT dept.
They may refer you back to AT$T due to the client. It may be missing a talking component so it misses some of the challenge which in turn results in failure.
Best of luck.
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