This is very interesting: are their bishops valid bishops? We’re they consecrated in the old rite by old rite bishops?
It is my hope that there is an ultra conservative underground church in China which A didn’t go along with communism and their “Catholic” church and B didn’t go along with V2.
The CPCA formed in the 1950s, so the bishops were certainly valid then. In fact, I think the penalty for consecrating a bishop without papal mandate was upgraded from suspension to excommunication due to the CPCA.
Bishops who opposed the CPCA were imprisoned for decades.
That said, the relation between the underground church and the CPCA is complicated. Some of the CPCA clergy are completely loyal to the CPCA, but others are not, and some clergy work in both. In one case, a CPCA priest was also a bishop in the underground church. In another more recent case, a bishop was consecrated with the approval of both the CPCA and Rome, and in his sermon during his own consecration, he announced he was resigning from the CPCA; this was a public insult to the govt and he was placed in "house arrest". Many CPCA bishops have reconciled with Rome with CPCA OK, but quietly.
Chinese Catholics have a tough choice. Go to the underground Church, which is loyal to Rome but now largely abandoned by Rome, where if caught they risk "re-education" or worse, or go to the Communist-led CPCA churches to be tracked and fed sermons that are at best bland and often propaganda.