I only view the first movie as definitive canon. After that everything gets messy with big leaps of logic, enough plot holes to make swiss cheese blush, and things that make little sense within the context of the original.
We have
the six new adventures. Disney pretends this doesn’t exist as its not a Disney creation.
the timon and pumbaa show doesnt even pretend to be remotely canon.
the first dtv sequel, which adds a bunch of characters that apparently existed in the timeline of the original but were never a part of the original. I like Kovu and Zira enough to pretend that they were on vacation in Hawaii when the battle for pride rock happened.
then the broadway show, which i consider to be a seperate entity from the rest.
then we have the second dtv sequel. I consider it to be a ‘what if’ story and not something that compliments the original.
then we have kingdom hearts 2, another part i consider to be a seperate entity.
then we have the lion guard. oh boy where do I even begin with this one?
But I like the first sequel and the lion guard enough to want them to be canon.