When my companions do not wear any equipment they show this damage reduction:

 

Grieving Mother: DR3, crush 3, pierce 3, fire 2, corrosive 2 (it is strange that fire and corrosive are shown because they are the same as the base value)

Sagani: DR6, pierce 8, cold 8, 3 corrosive

Hiravias: DR2, slash 3, fire 7, corrosive 1 (he has +5 fire DR through a talent he already had when I met him)

Pallegina: DR -2, pierce -3, fire -2, cold -2 (negative, fire and cold shown though the same as base)

 

All other chars have a base DR of 0 as it should be.

 

I think I found the reason.

These 4 chars wear an enchanted armor when they join the group. All of them wear a fine armor. The resistances that are modified are the same as the ones of their starting gear.

Somehow the DR modification of the enchantment have been applied permanently to the char. In case of Hiravias, the DR enchantment has also affected the fire DR caused by his talent. Maybe this is related to the infinite stat stacking bug.

 

Has anybody tested if their base DR is strange when you never save or load in the area where you find them before and after they join the group?

 

It is strange that Pellagina has a negative DR. All Other companions stand somewhere and they join you when you talk to them. You meet Pellagina twice before she can join you (in front of the building and inside of the building where she will finally join you.) Maybe this is part of the problem.

I just noticed this as well, when recruiting Pallegina for the first time.

 

It seems that the problem is with a badly designed equipment system, which doesn't properly calculate the stats for various characters, since this problem is repeating in different forms in many other places as well.

 

How it works now:

- Add bonuses on function calls

- Remove bonuses on function calls

-> When you forget to add the proper function calls to certain situations, you miss some of the information, hence you've got bunch of broken stats.

 

How it should work:

- When loading a character: calculate all stats based on basic stats and any possible modifiers.

- Re-calculate when required.

 

Of course it could be something completely different, but that feels like the most probable cause for the problem at the moment...