For context I'm a .Net Senior Software Engineer and Team lead. I recently started my current position and the majority of my team members are performing well. However, due to the general shortage of .Net developers our dev manager decided to hire a Java developer with limited SE experience, no prior mentorship and no training or experience with any of our tech stack's languages or tools.
If they had hired them as a Junior SE I wouldn't be having a problem but because they technically had 2-3 years Java experience (albeit with no one to mentor or train them during that time) they were hired as a mid level developer.
My problem is that management is expecting their output to match that of a mid level developer despite a lack of relevant training or experience. They have only been with us for 3 months, and before I was made their team lead, the prior lead reported to management that they didn't think they were passionate enough about programming and that they weren't learning fast enough.
They are close to reaching the expected capacity for a mid level developer and is retaining things they learn, which does justify their being a mid level SE. They also have one of the best attitudes I've ever encountered and is easy to teach and work with, but their reputation has already taken a hit.
How can I approach resetting management's expectations and opinions about this team member?