Guess I'll ask the obvious ones first... are you sure you have the full virtue armor set on (8 pieces)? Self repair only kicks in when wearing the whole suit.

As for the shield, do you have parry? Or are you human, so that jack of all trades gives you at least 20 parry?

The way self repair is supposed to work is that the item is repaired when it takes damage, as in SR4 would mean once the item takes damage, it's repaired by 4 points. Not sure if this kicks in with every bit of damage, I doubt it does. Otherwise SR 1 would be all you ever need.

Anyhoo, items won't repair while inside a container, because they have to take damage to do so.