Potency only affects if it is a hit. Accuracy Is what affects dodges.
Two checks for 100% chance debuffs;
first to see if the hit is successful check is accuracy vs dodge stats
Second to see if debuff is resisted check is potency vs tenacity stats
Three checks for less than hundred percent chance debuffs, second check becomes RNG check to see if debuff is even applied , 3rd check is potency vs tenacity to see if it is resisted (you will see resisted when that fails)
To increase accuracy, use arrow accuracy mods and R2 (passive increase of accuracy by 10%) combined is 22% accuracy
max dodge in game is 20% provided by zeta DM and 2% base on all toons. So 22% accuracy should hit most of the times.