Hi,
thanks, I have tested it with the Zibo 737 now and it seems, this is a viewing issue in the Zibo FMC. I can reproduce it:
Here, what you see on the main arrival page (I see also the RNVZ 20, which is incorrect and we don´t offer it as RNVZ 20):

… but when you select the RNVZ 20 approach, you will see only the offered RNV 20, without the Z postfix:

It looks, that the Z comes from the previous procedure. So, please report this to Zibo, it looks like more an issue on his side.
Here what we offer in the data and here you see no Z in the data, which is correct:

Hope that helps, but this is not a navdata issue - hopefully Zibo can help.
Cheers,
Richard