Around 50:40, Leif leans into Eddie's shoulder and falls asleep. When the camera pans at 51:10, Leif is gone.
The Paris casino does not have a strict dress code. Eddie would have had no problem entering the casino in what he was wearing.
About half an hour in as Eddie and Venom are walking through the Nevada desert there is a shot of a Bearded Dragon lizard. These lizards are only found in the wild in Australia.
When arriving in Las Vegas, there are fireworks going off. An aerial shot shows the fireworks exploding in incredibly close proximity to buildings, which would not happen in real life due to safety concerns.
When Eddie and Venom are falling from the airplane, Tom Hardy's English accent clearly comes through a couple times during their exchange.
In an establishing shot of Las Vegas, you can see the Sphere, a structure completed and opened in 2023. However in the movie Eddie mentions that he and Venom have been together for a year. The first Venom movie takes place in 2018 so that makes this movie take place in 2019, 4 years before the Sphere should exist.
In the first Venom film, symbiotes (the Kylntar) had to find a compatible host to survive on earth and have successful "merges" with said host. The first film showed several failures resulting in the host's death, inferring that a compatible host and merging is a rare occurrence. However, by this third installment, there is no explanation as to how or why the symbiotes in the lab battle successfully merge from host to host without the hosts dying.
During the battle in the lab, a symbiote saves Jim the security guard's life after the Xenophage impales him by fusing with him. That should have created another codex, but apparently doesn't.