Despite other flaws, the biggest (or maybe second biggest) issue I had with Solo was Lando's backstory.
See, I grew up reading some very old, very obscure EU books about Lando. In that series Lando was an expert card player but a poor pilot, and a lot is made of how he won the Millennium Falcon in a game of Sabacc but has no idea how to fly it. The movie reversed this, making him a card cheat.
I'm probably they only person in the world who cares.
But maybe new series, if it ever comes out, will be about Lando and his adventures with Vuffi Raa?