Each I launch blockbench, the first geckolib model project I open isn't recognized by blockbench. It shows that this model is made by "animated_entity_model" and unavaialbe in my blockbench. I need to install correct plugin. (I have installed geckolib plugin!).

The projects I open afterwards are recognized correctly. As long as I don't close the blockbench app, it can correctly recognize any geckolib project. Once I close blockbench and reopen it, it can't recognize geckolib project again.

I'd ask about this in the blockbench discord
Afaik this is caused by blockbench not loading the plugin

If they come back saying it's on our end I'll look into it