Real-World Example in doc

[HaveF]

Hi, There, Thanks for this repo,

I find I can't make the Real-World Example in Doc works as expected, even I add lots of fmt.Printf

https://go.dev/play/p/imrQXHVVR9T

the program should get id2 and id3 processed. But I only get ID2 processed. Did I screw up something?

Processed Customer: {ID:2 Name:Jane LastName:Smith Age:25 TaxNumber:TAX2}

[HaveF]

Maybe I find the spot, but don't know how to fix it.
If I comment the line rxgo.WithPool(3), // Increase concurrency, the result is fine.