The pass.telekom.de only shows a page displaying my remaining data volume for that month - so I wonder what it actually does as an error response.
The missing data are pre-selected in the comment lines. For telekom you use
PROGMEM = internet.t-mobile (alternative: internet.telekom)
APN_Benutzer = t-mobile (alternative: telekom)
APN_Passwort = tm
I have checked the firmware version on the E-H and it seems to be the latest available.
Beelogger has modified the SSL Testsketch - will check now, where this takes us.