HKPS fails on GPG 2.1

[Juan Miguel Navarro Martínez]

Refreshing, receiving, sending and searching for keys using a hkps server fails with a "No keyserver available" error as seen in this debug:

  C:\Users\Juanmi>gpg -vvv --debug 1024 --recv-keys 88E2947F9BC6B3CF  
  gpg: reading options from 'C:/Users/Juanmi/AppData/Roaming/gnupg/gpg.conf'
  gpg: using character set 'CP850'
  gpg: enabled debug flags: extprog assuan
  gpg: DBG: chan_000000C8 <- # Home: C:/Users/Juanmi/AppData/Roaming/gnupg
  gpg: DBG: chan_000000C8 <- # Config: C:/Users/Juanmi/AppData/Roaming/gnupg/dirmn
  gr.conf
  gpg: DBG: chan_000000C8 <- OK Dirmngr 2.1.1 at your service
  gpg: DBG: chan_000000CC <- # Home: C:/Users/Juanmi/AppData/Roaming/gnupg
  gpg: DBG: chan_000000CC <- # Config: C:/Users/Juanmi/AppData/Roaming/gnupg/dirmn
  gr.conf
  gpg: DBG: chan_000000CC <- OK Dirmngr 2.1.1 at your service
  gpg: DBG: connection to the dirmngr established
  gpg: DBG: chan_000000CC -> KEYSERVER --clear hkps://hkps.pool.sks-keyservers.net

  gpg: DBG: chan_000000CC <- OK
  gpg: DBG: chan_000000CC -> KS_GET -- 0x88E2947F9BC6B3CF
  gpg: DBG: chan_000000CC <- ERR 167772346 No keyserver available <Dirmngr>
  gpg: keyserver receive failed: No keyserver available
  gpg: DBG: chan_000000CC -> BYE
  gpg: secmem usage: 0/32768 bytes in 0 blocks

It does not matter which hkps server is, I have tried hkps://keys.riseup.net as well. But if I use hkp, it works.

The certification file is added in the dirmngr.conf as below:

  hkp-cacert C:\Users\Juanmi\AppData\Roaming\gnupg\sks-keyservers.netCA.pem

And gpg.conf file is the one made at riseup.net but with 'default-key' changed to mine and the old 'keyserver-option ca-cert' option commented:
https://raw.githubusercontent.com/ioerror/duraconf/master/configs/gnupg/gpg.conf

I'm wondering if it is because gnupg-curl and its libraries do not come with gnupg2.1.1 for Windows installer as it does with GPG4win installer, and I assume GPGTools for Mac.