BA allows account with state length up to 80 characters to be created, but OA has a restriction of 32 symbols. "e-mail" field length in BA - 100 symbols, in OA - 64. That causes situation when account is created on BA side but is not created on OA, as a result all the related operations like order provisioning fail.
An issue is caused by the bugs with ids #APS-37392 ("Inconsistency between limits for same fields in PBA and POA, email"), #APS-38783 ("Inconsistency between limits for same fields in PBA and POA, state").
Both bugs are fixed in OSA 7.1 (e-mail field length changed to 64, state to 80). Until the bug is fixed it is required to shorten the value and recreate an account in OA (e.g. by triggering an event from BA or with OA API).