Hi Andres,
Apologies for the delay.
Based on my review of the current DSP Builder Handbook, it appears that Agilex 9 is not yet supported in DSP Builder as of Quartus Pro 25.1. I also tested this myself and was able to replicate your observation — Agilex 9 does not appear in the device list.
I’ve reached out to the Factory team for further clarification and am currently awaiting their response. I’ll keep you updated on the progress and aim to provide an update by mid next week, or sooner if I receive any concrete information.
Please let me know if you have any concerns or further questions. Thank you!