migration by copy of ~/.gnupg not working

[Herr Saalfeld]

Hi,

I though migrating my user GPG configuration onto a new computer should
be as simple as making a full copy of ~/.gnupg with rsync

rsync -av old:/home/me/.gnupg /home/me/

However, on the new computer, I see nothing when I call

gpg -k

So I checked for differences

gpg --version on the new computer prints

gpg (GnuPG) 2.2.20
libgcrypt 1.8.7
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<https://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Home: /home/me/.gnupg
Supported algorithms:
Pubkey: RSA, ELG, DSA, ECDH, ECDSA, EDDSA
Cipher: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH,
 CAMELLIA128, CAMELLIA192, CAMELLIA256
Hash: SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
Compression: Uncompressed, ZIP, ZLIB, BZIP2


on the old computer, it is almost the same

gpg (GnuPG) 2.2.20
libgcrypt 1.8.5
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<https://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Home: /home/me/.gnupg
Supported algorithms:
Pubkey: RSA, ELG, DSA, ECDH, ECDSA, EDDSA
Cipher: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH,
 CAMELLIA128, CAMELLIA192, CAMELLIA256
Hash: SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
Compression: Uncompressed, ZIP, ZLIB, BZIP2


The directory content on both machines is

$ ls -al ~/.gnupg
total 152
drwx------  4 me me  4096 Jun  3 13:41 .
drwxr-xr-x 93 me me  4096 Jun  3 11:55 ..
drwx------  2 me me  4096 Dec 22  2017 crls.d
-rw-------  1 me me  9400 Feb 25  2016 gpg.conf
-rw-r--r--  1 me me     0 Aug  2  2016 .gpg-v21-migrated
drwx------  2 me me  4096 Aug 30  2019 private-keys-v1.d
-rw-------  1 me me 31836 Apr  8 21:51 pubring.gpg
-rw-------  1 me me    32 Jun  3 11:30 pubring.kbx
-rw-------  1 me me   600 Apr 15 11:24 random_seed
-rw-------  1 me me  2582 Feb 25  2016 secring.gpg
-rw-r--r--  1 me me 49152 Oct 17  2019 tofu.db
-rw-------  1 me me  2040 Oct 17  2019 trustdb.gpg


Can anybody help me out here?

Thanks so much in advance!

Stephan