Firstly, it’s not “as Rome alleges” because Lutherans too believe in the Real Presence of Christ in the Eucharist. The True presence is also held by the Orthodox and Orientals, i.e. the majority of Christians since apostolic times..
Sorry, transubstantiation is strictly Rome’s gig, and a recent one at that. It’s terribly misleading to blur it with “real” or “spiritual” presence. Early “real presence” is indistinguishable from “spiritual presence,” which you must know Rome does not teach. I think Rome would like people to conflate “real” with “corporeal,” but that’s not required by logic, language, or Scripture. God is quite real, and He is a spirit. Said so himself.
As for Luther, he did consubstantiation, which is not transubstantiation and therefore anathema per Trent. There’s no Aristotelian substance swapping. Zip. Nada. As for spiritual presence, the Service of the Didache could work in any Reformed church in the world, and in most Baptist churches. Adoring the host? Not so much.