Are they saying their perfect imaginary being made a mistake? And if “it’s the devil’s work”, is it so weak that it can’t prevent it?

The usual answer to this is that God gave man free will, and he can use that free will to act against God (or else the garden of Eden myth would be impossible) and if you choose to be gay, that's on you. That being LGBTQ+ is a choice is pretty fundamental to it, and also why they tend to believe in things like conversion therapy - if it's a choice, you can be taught to choose differently.