one of my pets ( https://www.sylestia.com/view/pets/?petid=455886 )
is lv 70, but their experience points far exceeds the amount needed to become lv 71 but she still does not lv up for what ever reason.

Hi!

There is no Level 71 currently, all the pets are capped at Level 70, but they still continue to earn experience points.

My Light pet has 160,697,521 / 2,698,176 exp, he should be like a level 80 but it's capped XD

The only enemies that exceed the Level 70 cap are anything post-Behemoth in the Lost Grove