The quotation is sent and then nothing happens
Ask a factory sales team what happens after a quotation goes out and the honest answer is usually that they wait. There is a belief, quite deeply held in technical industries, that a correct quotation at a fair price should not need chasing, and that following up looks desperate to a professional buyer.
In practice the buyer is comparing four quotations, two of which arrived with a test certificate attached and a phone call the following week. The quotation that was left alone is not evaluated badly; it is simply evaluated last, by somebody who has already formed a view. Almost all of industrial lead nurture follows from fixing this one habit.