Trivial thing. Why there's the option to vote your own post if it's not allowed? There's some rationale behind it?
From a UX point of view it seems to me that the function should be just disabled, instead of letting you click it and then show a message that you can't do it.
This was status-declined a decade ago on Meta SE: Remove vote UI elements beside own question and answer posts. It might be worth it to try flagging for it to be reviewed (following What posts should be escalated to staff using [status-review], and how do I escalate them?).
