Hello friends, in the course of adding bitcoin as a mean of donation for a non-profit, I came across with something I could not find an explanation.
I am using Bitcoin Core v0.16.1. The wallet has several addresses in the right format, and others with an unknown format.
They all validate just fine, the hdmasterkeyid is the same for the valid addresses as for these other, but I know are not valid.
Additionally, a valid validated address, whose validation output reads below contains an embedded address similar to the one right below.
Can anyone explain me what are those invalid addresses, their use, and the reason they were added.  Thanks a lot!

------Start insert invalid------
{
  "isvalid": true,
  "address": "bc1q5cwyt5gvjd7hjdqjlgxy8c08d3guk7gzdmk6tq",
  "scriptPubKey": "0014a61c45d10c937d793412fa0c43e1e76c51cb7902",
  "ismine": true,
  "iswatchonly": false,
  "isscript": false,
  "iswitness": true,
  "witness_version": 0,
  "witness_program": "a61c45d10c937d793412fa0c43e1e76c51cb7902",
  "pubkey": "02a8993288187150da1004e6eb446609b70256352191833cb010f3f0efd55f7968",
  "account": "",
  "timestamp": 1532141579,
  "hdkeypath": "m/0'/0'/3'",
  "hdmasterkeyid": "b8a1da04c8b60c4e169f725ab45a21688055d7e5"
}
------Ends insert invalid------

------Start insert valid------
{
  "isvalid": true,
  "address": "3M9vWs3GdoQmydabrVAcbPw2coWP8essnp",
  "scriptPubKey": "a914d5811b339742b7340e93e5b1d8e7892d0db7f80987",
  "ismine": true,
  "iswatchonly": false,
  "isscript": true,
  "iswitness": false,
  "script": "witness_v0_keyhash",
  "hex": "001438b84077c582438d6d49311b3ed236cfc8fe57c7",
  "pubkey": "03fabc1e47392c38bd8a5fb9305ecc7d435bab7a627f118c869928c85888cb79ba",
  "embedded": {
    "isscript": false,
    "iswitness": true,
    "witness_version": 0,
    "witness_program": "38b84077c582438d6d49311b3ed236cfc8fe57c7",
    "pubkey": "03fabc1e47392c38bd8a5fb9305ecc7d435bab7a627f118c869928c85888cb79ba",
    "address": "bc1q8zuyqa79sfpc6m2fxydna53kely0u478u4zcga",
    "scriptPubKey": "001438b84077c582438d6d49311b3ed236cfc8fe57c7"
  },
  "addresses": [
    "bc1q8zuyqa79sfpc6m2fxydna53kely0u478u4zcga"
  ],
  "account": "",
  "timestamp": 1532141579,
  "hdkeypath": "m/0'/0'/4'",
  "hdmasterkeyid": "b8a1da04c8b60c4e169f725ab45a21688055d7e5"
}

------Ends insert valid------