Don’t worry about chapter length. Think about scene length and content.
Go back a page and read this reply again. It's the one that got it right.
Many of us forget that books were originally serialized in newspapers with a new chapter posted every week, the writer getting paid a penny a word. In those days 5.00-50.00 a week was living very well indeed. Now you know why Dickens, Wilkie Collins and Bulwer-Lytton had such long books. The longer they spun out the story, the more money they made.
Varney the Vampire has over 100 chapters, I think.
Papers had space limits; the writers conformed to those whether it was 500 or 5000 words. The most popular writers could get away with longer chapters and did so. The papers enjoyed more sales and could afford to pay them.
In each chapter one or two major plot points / scenes occurred and ended on a cliffhanger so readers would
have to buy the next paper to see what happened.
That still works today: one or two plot points or a single major scene and end on a cliffhanger, big or small.
This is about *structure* and *pacing* -- not word / page count.
Genre doesn't matter. That's a guideline to follow for all books.
Fast or slow paced, you want readers cursing you because they were up all night reading your book. They planned to just finish the chapter, but you wouldn't let them.
Take a couple of hours and watch a few random soap operas. You'll find they push the plot forward at a snail's pace, but each scene, each episode, ends on a cliffhanger, big or small, awesome or totally lame, but the fans
have to tune in the next day to see how it is resolved.
If you outline or are a pantser (and a mega large fantasy should have at least a general outline) make a list of all the major scenes you need in your book. I use index cards on a magnetic board and shift them around.
MC confronts bad guy
BIG battle here
Bad guy dies
MC meets plot point character
Intro of magic whatsit
Dragon eats village
MC has internal crisis
Comic relief character gets into a jam
Those fantasy tropes are wildly out of order, but each is a scene you put in the right order to tell the story. Each scene is as long as it needs to be to accomplish its purpose, so disengage from word / page count and focus on craft / storytelling instead.