You said that they weren’t a valid church, thus how could the bishops be validly ordained if not a valid church? Were they invalidly ordained (you stated illicitly ordained) and than somehow made validly ordained later?
An ordination, like all sacraments, is valid if it is performed by a proper minister (in this case a bishop with apostolic succession), follows the correct form, proper matter, and proper intent. The were not ordained by the CPCA, they were ordained by a valid bishop, using the correct form, matter, and intent. This is not under dispute by anyone, at least as far as I know.
They were illicitly ordained, in other words a valid ordination was performed against canon law. In this case they were illicit because it did not have the Church’s consent (with Bishops, that means the Pope’s consent). When someone performs or receives an ordination without ecclesiastical consent, the incur a sentence of automatic excommunication. In other words, they entered into schism at that point. Subsequently, they made a request to Rome to re-enter into communion with the Catholic Church, pledging their loyalty to the Pope. This was granted, along with recognition of their position, and the excommunication was lifted.
Why does it confuse if there is an underground church that allegedly follows the Holy Se of Rome and a CPCA church that attempts to oversee but is an otherwise invalid church and thus claiming two churches? I don’t see how that confuses if your perception is that one church is legitimate and one illegitimate.
Because there are simply not two churches. The CPCA is not a church, it does not even claim to be one. Let me ask you a question and maybe this will help clear up the matter. Do you believe any bishop could be a bishop in two different Churches? I assume you believe the answer is no. Well, the CPCA Bishops are recognized as valid Bishops of Rome. So they cannot be bishops of another communist church. Nor do they claim to be so.
So anytime someone talks about the existence of two churches in China, a valid underground church and a schismatic government church, they are either misinformed or being misleading.