TOPIC:

My purchased AutoCAD 2024 plugins are not working in 2025.

If I purchased individual plugins for AutoCAD 2024 (like AutoLayers, MultiCopy) and upgraded to AutoCAD 2025, do I need to re-purchase all of the plugins for the new version?

Yes, you need to buy new licenses.
Licenses for individual plugins are perpetual, but only for one version of Autocad. A subscription is version-independent and gives access to all plugins, but with a time limit.
All license differences are described in Help - modplus.org/en/help/licenses