The traits that make you a great engineer — precision, skepticism, depth — are the same traits that will lose you deals if you don't learn to control them.
Every engineer who moves into sales carries a set of instincts built over years of technical work. Those instincts are real assets. They are also traps.
Your credibility is genuine. When you explain how something works, buyers believe you in a way they never believe a non-technical salesperson. That is a significant advantage. But the same instinct that makes you thorough makes you over-explain. The same habit that makes you precise makes you lead with features instead of outcomes. The same drive to solve problems makes you jump to solutions before you've understood what the buyer actually needs.