Plot hole: Mando thinks that the other Mandalorians are alive, that they will definitely help him (but then why didn't he contact them?), and even presumes that they are still hiding in the same sewers as before, when it was stated at the end of 1-3 that they'd have to relocate, and he knows now that the planet is under imperial control. Still, he is not wrong, and despite most of the Mandalorians having died, their precious armor lie there even days or weeks after.
Plot hole: The boss of the boss murders Werner Herzog because he knows that the baby is not in the crib. Yet it takes Mando's message (somehow intercepted) for the troopers to start moving in pursuit. The heck were they waiting for? They have overwhelming forces in the area and a previous deal with Karga. (00:33:10)
Plot hole: Nick Nolte's little guy is supposedly terribly helpful towards Mando, showing him "the only way" to reach the enemy encampment, which is by riding the weird fishy beast, but when Mando surveys the target and the robot reveals itself, you can see that there are only shallow hills around the base, a large clear path of land, nobody even is on lookout...and most importantly, in the following episode, Mando makes it back on foot anyway, no blurrgs - and evidently the baddies had no vehicles, making them even less of a threat to begin with. And for being so helpful and good natured, he did not tell him to park the ship by/at his place nor warned him about the Jawas.
Other mistake: "Blue" checks out Cara Dune's record and talks to her in stellar terms, obviously she's a great gal. When Mando and her met in episode 1-4, Cara said that if she even tried to board a vessel registered with the New Republic, she'd be captured and be put in jail for life.
Other mistake: Somehow during the episode Cara and Fennec, on foot, manage to get to the base at the same time as Mando, who is on a truck. Moreover, Cara is the one with Mando's armor in a sack, but when Mando emerges from Slave-1, he changed clothes, and he's back in full uniform.
Character mistake: Cobb Vanth says that he's never seen anything but the dragon's head and had no idea about the size of the dragon...but at the beginning of the episode we could see the beast pass through town (conveniently right in the main road without damaging anything else) and its enormous lengthy body was perfectly noticeable. (00:31:20)
Plot hole: The Client does not care if The Child lives or dies, in fact he sent out bounties for the baby to be delivered dead, without even offering the incentive. But as if it were an SNL spoof, he is slowed down by Greef Karga's comment about the baby being asleep. Pretty amazing to begin with that the crib, aka an object completely sealed that could contain anything from a bomb to some form of killer droid or a stash of weapons, is allowed in without the faintest inspection. Not to mention that he is loaded with tracking fobs for the baby. He should be alerted just by not hearing beeps from the devices.
Continuity mistake: Preparing to walk into the Client's compound, Cara wraps a cloth around her tattoo. The shot of the crew walking away from Kuiil (half of his head in the foreground) shows Gina Carano not wearing any bandage, the tat fully visible. (00:26:45)
Plot hole: Kuiil is shown salvaging the droid from the building's ruins. A campfire is still burning and the droid's remains are still smoking, but at the end of the mission he spent a couple days at least with Mando on the jawas' sidequest. The only time when he could have got the robot when the ruins were still smouldering would have been right after Mando left, but that implies he's been a huge jerk not giving him a ride, and lied to him when he acted surprised he was still alive - it's also impossible he could have had the droid on his property without Mando seeing it and freaking out. (00:09:50)
Continuity mistake: In the scene with all the Mandalorians just hanging out at some bar, Boba Fett retorts at Sasha Banks' character; "if it isn't the quacta calling the stifling slimy." There's a cut and his rangefinder is inexplicably tilted forward. It is back to normal in the rest of the scene. (00:06:15)
Visible crew/equipment: The kid actors in the school scene several times break fourth wall looking very distinctly at the camera. The kid directly behind the Child does it right away as Carl Weathers brings it there, and when Gina Carano is heading out there's a kid in the foreground who steals a worried peek at the camera, impossible not to notice. (00:09:05)
Continuity mistake: At the end, when The Mandalorian takes his helmet off so Grogu can see his face, the helmet is placed on the floor facing backwards. When Grogu is placed on the floor, it is now facing forward. Then when Luke walks away, the final shot shows it facing backwards again. (00:36:50)
Plot hole: Seeing The Child in episode 2-1 minute 10, Amy Sedaris' character shouts "Thank the Force." Up to that point nobody seemed to have the faintest idea of what sort of mysterious energy Grogu was using. It gets worse in episode 2-3 when Mando uses as greeting for the New Republic "May the Force be with you", which is used later other times. With the concept of Force being this ingrained in people's culture, it's inconceivable that *everyone* is completely clueless about Jedi, especially considering that Order 66 with the Jedi purge happens barely 30 years before the events of the Mandalorian, and several characters such as Kuiil or Greef Karga were alive and active during the time when Jedis were powerful and part of the administration.
Plot hole: The Imperial terminals have facial scan recognition...or just facial scan, really, since ANYONE regardless of being part of the army or not can just access any information of any level, as long as they have ANY face that the app can scan and identify as not being a known criminal.
Plot hole: When the distress signal is launched, approximately 20 minutes are left till the arrival of the New Republic fleet. From the control room the team arrives to the prisoner's cell with 15 minutes to spare. They lock Mando up, and next time they communicate with their getaway robot dude, it says there are only 10 minutes to go, meaning it took them an astonishingly long time to navigate the ship without being really much closer to the exit, having met no opposition. Then the episode turns into a slasher movie of sorts, and somehow Mando manages to find them separately, hunt them down and as it turns out, not simply disposing of them, but also drag their unconscious carcasses to the empty cell he escaped from. There's nothing coherent about this timeline.