this may need to be verified as im running a mod pack, but using forge version 1.19.2 hoppers (vanilla), transporters (mekanisum), and chutes (create) wont input coal into the coal generator.

i have not been able to find anything that supports into into coal generators

Can't reproduce. Is there any other info you can provide?

i will look more into this and do testing on my side

after lots of testing
this is caused by an conflict with the mod canary mc https://github.com/AbdElAziz333/Canary that aims to optimize, while its installed, input and output on ad astra blocks breaks. i will make a issue request on canary.

for record keeping, and your own knowledge, here is the report i put out for canary, regarding the compatability issues with this mod. AbdElAziz333/Canary#61