Well, I’d say it’s either a D16 bug with Windows 11(?), so submit a ticket or check the D16 forums for similar user issues, or your AMD processor and RAM aren’t powerful enough to manage these types of plugin power hogs.
Not helpful to you right now, but with apple silicon you can use many multiple instances of these types of plugins without breaking a sweat - here’s an old thread I posted that shows how much load they can take : Apple goes to ARM - #2135 by Jimbo
Having Diva playing on one track with 15-20% cpu usage is not a good sign for your cpu’s power capability. The above thread shows 25% average cpu draw with a shit ton more tracks and power hungry plugins running.
3 year old M1 macs are more than up to the task of this kind of performance and are pretty cheap to buy second hand now.
Hope that helps in some way 