Per the top FAQ here, that is how it's supposed to work. It sounds like it must have been a bug that was allowing you to recycle intermediates in the lower tiered machines, because I changed that all the way back in v6.1.0
My saved game was using the 7.0.10 version and it worked (melting plates into ore).
But when I start playing again recently, with the updated version, this factories stop working...
I tried 8.1.0 and also doesn't work. But when I tested 8.0.0 it worked!
Because of that I thought it was a bug!