You're not aggressive — you're vague. Your follow-up just re-pitches the same line as DM-1 with "bumping this." Most of your replies came from people who got a fresh hook on day 4, not a nudge.
Three concrete moves:
• Replace "bumping" with a new angle — a stat, a question, or a callback to their pinned tweet.
• Cut DM-2 to under 280 chars. Yours averages 410.
• Shift the CTA from "hop on a call?" to a low-friction question they can answer in one line.