Leveling scaling question

I’m playing on Expert. I’ve been having zero issue killing mobs, elites, bosses, hell tide boss, etc. I hit level 40-44ish and now I’m getting absolutely rekt by everything. My armor is capped. Resists are decent, near 70. Have tempers, aspects, the works. Why the hell am I squishy as hell now?

If you free squishy go back a difficulty level. Higher difficulty is just a gear/build check.

You still need damage reduction