I know everyone has different views on both worldbuilding and characterization, and especially on the idea of consistency in both, but I wanted to share my feelings on both of them (which are kind of the same! people and places are sort of the same thing sometimes).
Consistency, to me, is about three things: rules, guidelines, and lies.
Rules are things that (whether they've been told explicitly or not) are immutable. They are the law of the land, and you don't break them. You don't actually need to tell the reader what they are, but you should know what they are. They can be simple or they can be extremely complex, but they are things that you stick with. Unless stated otherwise, readers will generally assume that the rules of the real world apply to your story.
For the world, that might be "water is H2O" or "mountains will not stand up and turn into giant creatures and walk away" or "vampires and werewolves can cross-breed but only if they have sex during a new moon" or whatever. For a character, that might be "this character will not kill under any circumstances, no matter what" or "this character won't every tell their parents about that one time they committed arson." It's easier to do never rules for characters than always rules, but you can do both.
Guidelines are things that generally happen but aren't a requirement. This is where people tend to get caught up in character/worldbuilding consistency. Most character traits are going to be guidelines, not rules, because most people do have exceptions or things that change their mind or just character growth. Most things in the world don't work exactly the same way 100% of the time. But there generally needs to be an implicit or explicit explanation for the guideline not being followed, or it just feels like the author screwed up.
For the world, these might be "water isn't flammable--except in those cases where it is" or "vampires and children can't have kids, except in those super rare cases where they can" or "that one time, a mountain stood up and walked five feet and sat back down, but other than that it's never happened so we're pretty sure it'll never happen again". For a character, that might be "this character's instinct is to run away from things that scare them, but this one time they will overcome that instinct to protect someone else" or "this character is generally happy-go-lucky but right now they are deeply sad because something tragic has happened".
Lies are where it gets fun. Lies are things that you have presented as rules that are actually not. Somtimes this is because a character is literally lying to the reader or to other characters, sometimes it's because characters don't have full information, and sometimes it's because some other factor has changed.
For the world, this might be "only people from the royal family can bond with dragons because they have been genetically modified to bond with dragons--oh, actually, that was a lie perpetrated by the government to keep people from trying to bond with dragons" or "there is no eighth continent on Earth--actually there is, it was just hidden from view by magic". For a charcter, this might be "this character would never under any circumstances kill someone--except they just did."
The thing about lies is that they need to have a good in-universe reason behind them, and they can't conflict with other rules you have. I always go back to Stephenie Meyer when I think about this. Early in the series, she set up two rules that she told the reader explicitly: 1) all of vampires' fluids are venom and 2) vampires have 25 chromosome pairs, werewolves have 24 chromosome pairs, and humans have 23 chromosome pairs. The lie that vampires can't have children with humans runs into the issue that it's in direct conflict with those two rules above--but those two rules are never rescinded. So it doesn't feel like a lie so much as it feels like an inconsistency. It feels like she messed something up.
When you're thinking about internal consistency, consider:
Is something a rule, a guideline, or a lie?
If a guideline isn't being followed, is it clear why (e.g., is it an exception? character growth?)
Does the lie conflict with other rules in the world?
What does the lie or the exception to the guideline accomplish?