So I ran a Wlk, lvl 21 through parts one and two, normal elite. Ransacked every chest, busted every breakable, etc.
By the middle of part two, my toon with only a 12 strength was overburdened. I thought it was the "regular" loot, but I only had 2 suits of armor, which the stats show was not that heavy.
No, the weight problem was the pieces of chain. I did not look exactly how many I had collected-- 3-5 per chest? 6-7 chests? 30? A wild-888 guess.
But the issue seems to be they are too heavy, for a collectable.
Elsewhere I see that you need 400 of these?
If that's true--there is no way in the game, a single character could walk, once they put all 400 pieces into their backpack-- even with a 20-25 strength!
Yes-- I finished the run by quickly buying a strength tome-- (L-TP is free, after all) but this is a bug, IMO.