I have tested some stuff my self and I dont think the problem is with the DLC injector. I created a character with the blank DLC save and it still has the same issues / crash. Just in case here is the crash message I get in Ryujinx console.
I had a similar problem where no monsters were on the map, in addition the quest start chest was empty and I crashed after abandoning the quest (only tried once on "A Season For Lava"). I have attached my save data before the insert. I am not HR10+ but I did not want to lose the progress so far...