Resolution:
Timezone is optional according to the ISO 8601standard. We simply do not handle the additional timzone field supplied here.

You can format the current-DateTime() as follows to make it SDK DateTime format compliant:

tib:format-dateTime("yyyy-MM-DD'T'HH:mm:ss.SSSSSS", current-dateTime())

SDK throws following Marshall Error:

Exception = AESDKC-0013, Message = The parameter value supplied is invalid: Date
must be in YYYY-MM-DDTHH:MM:SS or YYYY-MM-DDTHH:MM:SS.SSSSSS format: 2005-01-27T15:29:16.069-08:00