Can't 'git push' but SSH appears to authorize?

Hi,
It seems like the the ssh command when used with GIT is not using the IdentityFile from your ssh config file. These are two different ssh commands. (OpenSSH_for_Windows_7.7p1, LibreSSL 2.6.5 vs OpenSSH_8.0p1, OpenSSL 1.1.1c 28 May 2019) It might not support the %d syntax there. According to the log you posted, it tries these private key files for authentication:

debug1: Will attempt key: /c/Users/████████████/.ssh/id_rsa 
debug1: Will attempt key: /c/Users/████████████/.ssh/id_dsa 
debug1: Will attempt key: /c/Users/████████████/.ssh/id_ecdsa 
debug1: Will attempt key: /c/Users/████████████/.ssh/id_ed25519 
debug1: Will attempt key: /c/Users/████████████/.ssh/id_xmss 

You can check if the %d is not supported, but changing the line

IdentityFile %d/.ssh/keys/balena_legowerewolf

with

IdentityFile /c/Users/████████████/.ssh/keys/balena_legowerewolf

or

IdentityFile ~/.ssh/keys/balena_legowerewolf

Cheers,