Gave wasteland roamer quirk to all 4 of my created characters but resistances show 0% under the stats list. Is this working?

Armor mod resistances do appear in the stats list but the multiple 100% resistances you should get for the quirk are not displayed.

That perk gives resistance to certain status effects. They DO NOT affect direct damage resistance.
If it makes it easier, think of it this way.
Bleeding, poisoned, shocked, burning (that the perk protects against) apply damage over time.
Fire, Ice and Energy apply direct damage.
They are not the same thing.

It's working as intended.