Yeah...they really do, come to think of it. Right after Simba matures the tone changes dramatically. Enough that they managed to make a whole film in the middle. I haven't seen TLK 1½, so I wonder if it smooths over the abrupt tonal shift.
The original movie is a classic but I enjoyed Simba's Pride. Kovu is probably the only feral style animal character I actually find kinda sexy, haha. The new characters it introduced are all pretty interesting. I liked Nuka a lot (even though his VA is a literal Dick.)