I used to go to a Protestant Three-Self (legal) church when I lived in Wuhan. You hear and read all sorts of horrible tales but I never saw any direct persecution.
Where churches got into conflict was with things like building permits. To get those you have to pay a bribe to get to the front of the line. This is true of everyone not just churches because bribes are just ubiquitous when dealing with the party. The church wouldn’t pay the “tea money” so they could never get the paper work filed. The way they worked around that was to find out who the clerks were and where they lived and then evangelize them.
Catholic experience may be different