Ok so I understood that the previous easybbpstake took 4M UTXO as it was the closest over 50K.
This prevented me to create the Dash stake because after this, I have no more unused BBP 
10:50:48

getpin XuaM6msExXfzojwv9KBtwdiRtfhPoFyWDZ 
10:50:48

{
  "pin": 20379
}
11:08:34

easystake 200000 XuaM6msExXfzojwv9KBtwdiRtfhPoFyWDZ 0.40020379 0
11:08:34

{
  "BBP UTXO": "b2d89fb027b0970d9d80b4bf528de14410efecfd9637df4886beefe28977661e-1",
  "BBP Address": "yiA3T65AH5Nu1ztVzNvrmmMoeKZFttAaP3",
  "BBP Amount": 3999998.98741,
  "Foreign Symbol": "DASH",
  "Foreign Amount": 0.40020379,
  "Foreign UTXO": "6de59866edb9761c875b9c7f3ab93798f71a1924ea12c869cac9806a2b10f79f",
  "Foreign Ordinal": 1,
  "Foreign Value USD": 43.79861399117564,
  "BBP Value USD": 203.7647689884451,
  "DWU": 4,
  "Pin": 20379,
  "pin_valid": true,
  "Error": "",
  "Dry Run Mode": true
}
11:08:46

easystake 200000 XuaM6msExXfzojwv9KBtwdiRtfhPoFyWDZ 0.40020379 1
11:09:08

{
  "BBP UTXO": "b2d89fb027b0970d9d80b4bf528de14410efecfd9637df4886beefe28977661e-1",
  "BBP Address": "yiA3T65AH5Nu1ztVzNvrmmMoeKZFttAaP3",
  "BBP Amount": 3999998.98741,
  "Foreign Symbol": "DASH",
  "Foreign Amount": 0.40020379,
  "Foreign UTXO": "6de59866edb9761c875b9c7f3ab93798f71a1924ea12c869cac9806a2b10f79f",
  "Foreign Ordinal": 1,
  "Foreign Value USD": 43.79861399117564,
  "BBP Value USD": 203.7647689884451,
  "DWU": 4,
  "Pin": 20379,
  "pin_valid": true,
  "Error": "",
  "Error (Not Sent)": "Duplicate BBP UTXO. "
}
But at least we can say the system works, it picked the correct Dash UTXO id and checked the pin correctly.