Not working inside tmux

Agent seemingly working just fine from a bare terminal (kitty), not working from tmux. I get the following log lines:

1password:
```
WARN 2022-02-15T13:53:26.388 tokio-runtime-worker(ThreadId(3)) [1P:foundation/op-sys-info/src/process_information/linux.rs:340] no top-level parent was found for pid 81229
WARN 2022-02-15T13:53:26.388 tokio-runtime-worker(ThreadId(3)) [1P:ssh/op-ssh-agent/src/lib.rs:261] Unable to get client_info for pid: 81229


ssh -vvv:

debug1: Next authentication method: publickey
debug1: Offering public key: /home/$USER/.ssh/pub/1password_REMOVED_rsa.pub RSA SHA256:REMOVED explicit agent
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 60
debug1: Server accepts key: /home/$USER/.ssh/pub/1password_REMOVED_rsa.pub RSA SHA256:REMOVED explicit agent
debug3: sign_and_send_pubkey: RSA SHA256:REMOVED
debug3: sign_and_send_pubkey: signing using rsa-sha2-512 SHA256:REMOVED
sign_and_send_pubkey: signing failed for RSA "/home/$USER/.ssh/pub/1password_REMOVED_rsa.pub" from agent: agent refused operation
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
$mailto:USER@REMOVED.org: Permission denied (publickey).
```

config looks like this (for the two config blocks that actually match this connection):
```
Host REMOVED
IdentityFile ~/.ssh/pub/1password_REMOVED_rsa.pub
Hostname REMOVED
User $USER

Host *
IdentityAgent ~/.1password/agent.sock
IdentitiesOnly yes
ForwardAgent no
TCPKeepAlive yes
ServerAliveInterval 15
ServerAliveCountMax 6
AddKeysToAgent confirm
UpdateHostKeys yes
HashKnownHosts no
NoHostAuthenticationForLocalhost yes
IPQoS=lowdelay
ControlPath ~/.ssh/mux/master-%l-%r@%h:%p
ControlMaster auto
ControlPersist 4h
```

---

1Password Version: Not Provided
Extension Version: Not Provided
OS Version: Ubuntu 21.10