Git ls-remote to github fails with classic "SHA-1 not supported" on tunneled ssh session but `ssh -T git@github.com` doesn't

Cross-posting from [here](https://stackoverflow.com/questions/78737977/git-ls-remote-to-github-fails-with-classic-sha-1-not-supported-on-tunneled-ssh?noredirect=1#comment138823224_78737977) as suggested by the community. A bit of context: At my company we do tunneling to ssh into EC2 boxes. This tunneling command is as usual, uses ForwardAgent and the proxycommand is something like this: ProxyCommand ssh tunnelhost exec nc %h 22. Some other configs are:

AddKeysToAgent yes
UseKeychain yes
IdentitiesOnly yes
UserKnownHostsFile ~/.ssh/known_hosts
HostKeyAlgorithms +ssh-rsa,ssh-dss,ssh-ed25519
PubkeyAcceptedAlgorithms +ssh-rsa,ssh-ed25519
KexAlgorithms +diffie-hellman-group1-sha1
PubKeyAuthentication yes
# IdentityFile ~/.ssh/id_rsa
# IdentityFile ~/.ssh/id_ed25519
IdentityFile ~/.ssh/id_ecdsa

As you can see, I already tried RSA, ED25519 and ECDSA keys (all of them added to GitHub) and it seems like my key is not the issue. **The problem:** The issue is that, if I do a git ls-remote --heads git@github.com:company_org/repository.git I keep getting the error:

ERROR: You're using an RSA key with SHA-1, which is no longer allowed.
Please use a newer client or a different key type.
Please see https://github.blog/2021-09-01-improving-git-protocol-security-github/  for more information.

I know my key is not SHA-1 but still keep getting this error. To confirm my theory (that my key is fine) I used (following github's guidance) the ssh -T git@github.com command and I see it's working as I receive the correct response:

Hi stoicAlchemist! You've successfully authenticated, but GitHub does not provide shell access.

I have a feeling that the server might have a conflicting config somewhere but I don't know where to look. More Context: It seems that I'm the only one on my team that is having this issue, the other engineers don't have an issue, that's why I'm leaning towards a config. I already tried changing keys, and even tried different types, changed configs to see if any of them were to blame but with no luck.