Your tablet of containment ritual isn't working. When I activate the ritual all it says is awaiting activation. I have placed the mob I want to capture next to the ritual brazier, but the ritual next starts. I have even put full source jars next to it thinking that will fix it but nothing happens. When I break the ritual brazier I always get my tablet back. I'm not sure if that is supposed to happen. I have watched Direwolf 20 do this ritual multiple times and from what I can tell I'm doing it right.

Awaiting activation means it is waiting to be started. Right click with an empty hand to start it.

Some rituals can be augmented before being started, that one cannot.