Too much exposition killed it for me. Author is blowing his load too much too fast. It's better to witness the lore with the plot/world/characters, instead of throwing in a wiki article every chapter.
it took 2.5 chapters to explain the dungeon instead of just going with it. sure she can explain it to the MC, but it doesn't need to be so verbose and the readers don't need a lecture.
Next up in the Solo genre we have; Solo Fishing, Solo Planting, Solo Mailreading, Solo Sitting In Town Trying To find A Party For A Raid But No One Likes You, and Solo Quitting.