Authority key not recognized in Ubuntu 18.04

[huertanix]

OS: Ubuntu 18.04.3
GPG Sync Version: 0.3.4

When adding GPG Sync details for FPF outlined, I get an Authority key is not found in keyring error.

I have confirmed that contrary to the error message, I do, in fact, have the authority key, downloaded from keys.openpgp.org in my keyring.

[huertanix]

Just tried this again and getting the same error. (._.)

[huertanix]

FYI this is the full output from running gpgsync --verbose and going through these steps:

gpgsync --verbose
[Settings] init: appdata_path: /home/huertanix/.config/gpgsync
[Settings] load: settings loaded from /home/huertanix/.config/gpgsync/settings.json
[Settings] configure_run_automatically
[GnuPG] init: created homedir: /tmp/tmptt7n0xtf
[MainWindow] init
[KeylistList] init
[KeylistList] update_keylist_widgets: keylist_widgets: []
[KeylistList] update_keylist_widgets: keylist_widgets: []
[AuthorityKeyValidatorThread] run: starting authority key validator thread
[Keylist] refresh_keylist_uri: Downloading https://raw.githubusercontent.com/freedomofpress/fpf-gpg-fingerprints/master/fingerprints.txt
[GnuPG] get_uid: fp=b'F81962A54902300F72ECB83AA1FC1F6AD2D09049'
[GnuPG] _gpg: args: ['/usr/bin/gpg2', '--batch', '--no-tty', '--homedir', '/tmp/tmptt7n0xtf', '--with-colons', '--list-keys', 'F81962A54902300F72ECB83AA1FC1F6AD2D09049']
[GnuPG] _gpg: stdout: b'tru::1:1571776748:0:3:1:5\n'
[GnuPG] _gpg: stderr: b"gpg: keybox '/tmp/tmptt7n0xtf/pubring.kbx' created\ngpg: /tmp/tmptt7n0xtf/trustdb.gpg: trustdb created\ngpg: error reading key: No public key\n"
[Keylist] validate_authority_key: Fetching public key 0xA1FC1F6AD2D09049
[Keylist] get_keyserver: self.keyserver=b''
[Keylist] validate_authority_key: keyserver=b'hkps://keyserver.ubuntu.com/'
[GnuPG] recv_key: using modern keyserver, fp=b'F81962A54902300F72ECB83AA1FC1F6AD2D09049', use_proxy=False
[Common] vks_get_by_fingerprint: 200 GET /by-fingerprint/F81962A54902300F72ECB83AA1FC1F6AD2D09049
[GnuPG] _gpg: args: ['/usr/bin/gpg2', '--batch', '--no-tty', '--homedir', '/tmp/tmptt7n0xtf', '--with-colons', '--with-fingerprint']
[GnuPG] _gpg: stdout: b'pub:-:4096:1:A1FC1F6AD2D09049:1516562848:::-:\nfpr:::::::::F81962A54902300F72ECB83AA1FC1F6AD2D09049:\n'
[GnuPG] _gpg: stderr: b'gpg: WARNING: no command supplied. Trying to guess what you mean ...\n'
[GnuPG] _gpg: args: ['/usr/bin/gpg2', '--batch', '--no-tty', '--homedir', '/tmp/tmptt7n0xtf', '--import']
[GnuPG] _gpg: stdout: b''
[GnuPG] _gpg: stderr: b'gpg: key A1FC1F6AD2D09049: no user ID\ngpg: Total number processed: 1\n'
[GnuPG] import_to_default_homedir: stderr: b'gpg: key A1FC1F6AD2D09049: no user ID\ngpg: Total number processed: 1\n'
[GnuPG] test_key: fp=b'F81962A54902300F72ECB83AA1FC1F6AD2D09049'
[GnuPG] _gpg: args: ['/usr/bin/gpg2', '--batch', '--no-tty', '--homedir', '/tmp/tmptt7n0xtf', '--with-colons', '--list-keys', 'F81962A54902300F72ECB83AA1FC1F6AD2D09049']
[GnuPG] _gpg: stdout: b'tru::1:1571776748:0:3:1:5\n'
[GnuPG] _gpg: stderr: b'gpg: error reading key: No public key\n'
[ValidatorThread] run: Error: Authority key is not found in keyring None

[huertanix]

I'm now seeing the same error in macOS Mojave using gpgTools. As you can see from the screenshot, the authority key is present in the keyring, but the error is saying it's not.