Have you tried Dream Theater? They are prog metal and have been putting out albums for 30 years now.

How about Nightwish? They are symphonic metal but many of their songs could also be classified as prog rock given the time changes and stylistic changes within the song. This song I'll link an amazing live version that makes you think your at a classical music opera for the first 1:20 or so and then the metal kicks in. Over its 14 minutes it hits multiple genres. https://m.youtube.com/watch?v=N4Vfy5yCy-c