Inaccurate count of sessions in `Copilot on My Behalf`

[bamurtaugh]

I have more than 20 sessions in this repo (I count 28 when I manually scroll through the PRs listed), but the summary here mentions 20:

I tried using the Load more and Refresh buttons, along with entirely reloading VS Code, but the number stayed the same at 20. I've had more than 20 sessions for several days, so I don't think it's a matter of trying to refresh too quickly.