Glory to Jesus Christ!
I can help a little, but the background requires more explaining than I can probably give justice to in one post.
The Polish immmigrants in many cities had a pretty rough time with their bishops ( the bishops probably would have said “those Poles are giving me a rough time!” LOL

).
Most of the bishops in the USA were Irish at one time, then the immigation of Germans created problems because the Irish did not necessarily sypathize with the special needs of these immigrants. Eventually there were some German bishops too. But by then the floodgates had opened to all kinds of immigrants after about 1850, among them were Poles and Slovaks, Mexicans and French Canadians etc.
There were also “Greek” Catholics too, mostly Slavic but also Lebanese and Syrians.
By the 1870’s these new immigrant groups were crowding the cities, and many were attracted to the Pennsyvania coal mining region, jobs at the steel mills and on the railroads.
Speaking of the Poles specifically, the Irish-American bishops often did not see the problems immigrants might have in worshipping, confessing etc. with a priest who didn’t understand their language and culture. Sometimes the bishop would not allow an ethnic group to build a church, they would tell the Bohemians, Slovaks and Croatians to go to the Polish church! This gave many people the impression that to the bishop “they all look alike”. But it also helped with the building plans of the diocese: bigger churches funded by a larger community.
In fact, I know that Ukrainian Catholics and Ruthenian Catholics were told to go to the Polish churches too, even though they had a distinctly different liturgical rite. (This appears to have been official church policy - no foreign rites may be introduced by any bishop, only that practiced by the Roman church)
There were other problems due to customs as well. Some of the same kind of problems we read about on the board today:
-Not happy with the priest assigned (doesn’t speak the language, doesn’t support our traditions)
-Bishops seem too (name it here)
-We give a lot of money but the bishop spends it all in the Irish neighborhoods
-Seminaries don’t accept all of our young people, but they make room for all of the Irish.
-We want bishops of our own nationality
The Byzantine Catholics had a lot of the same problems, finally (after Vatican I) there was a major schism among the Byzantines that might have been avoided if the group had been handled with more sympathy. They became Orthodox and eliminated Vatican I and the Irish bishops at the same time.
This same thing happened among the Poles, who probably felt the sting of prejudice and were likewise taken for granted by the bishops who expected blind obedience but might be accused of lacking in compassion. The Poles had some of their priests consecrated by Old Catholic bishops, and started an Old Catholic church for Poles in the USA.
There is certainly enough blame to go around. The immigrants would build a church and then be required to hand over the title to the bishop. These poor hardworking people just didn’t understand why they should turn over the deed to the property to the bishop! In an atmosphere of distrust they expected the worst, and sometimes their worst fears came to pass.
Here is a link to the
Polish National Catholic church, you may have already checked it out.
The PNCC has been in dialog with the RC for some time now, they sometmes appear to be close to reconciliation (I wonder if the repose of JP II will mean the dialog will come to nothing). Members of the PNCC are allowed to take the sacraments at RC churches without actually converting.
Some of the problems I can think of that might prevent a reunion soon are the fact that they ordain married men (not a big deal) and they will consecrate married priests to the Episcopate (a big deal). Also they hold title to the parish property locally, in the hands of the parish council, and they are very proud of this distinguishing characteristic. It is against the canons of the Roman Catholic church in the USA to hold property at the parish level, the practice is known as trusteeism and was the source of major problems in church discipline in the past. It seems to have been a major issue at each of the
Plenary Councils of Baltimore.
Interestingly, there is a Polish parish in
Saint Louis that is going through the classic ethnic crises, complete with a
contest with the bishop over who owns the property!
I hope that this helps.