Our Frigidaire washer has a strong `marsh` smell from inside. Odour is getting on cleaned clothes. Tried to clean it by running bleach through cycle. Any suggestion of what the problem is and how to correct itÉ

Frigidaire 'Gallery Series' has a serious design flaw in the round rubber boot seal. Looking in there, you will see the drain holes are NOT located at the low point in the seal. Not being in the low point, water collects there and has no place to drain. Hence the marsh / swamp smell.
Frigidaire customer service line does nothing to help, only saying you need to wipe out the area with bleach or other germ killing solvent with a rag. Nice solution.
If I need to buy a second washer anytime soon (if I get tired of this Frigidaire 'solution') I will certainly look for another brand that does not have this visible problem.
Now I know.

Keep the door open between loads to help dry away the moisture. The rubber seal locks in the moisture resulting in the smell

I had this disgusting problem and learned from a chemist on line:
1) Use HE detergent.
2) Use a TINY amount of detergent.
I use about a tablespoon = 2 short pumps on the Tide dispenser. It is sufficient to totally clean the clothes without feeding the black mold. You will be surprised. The chemist described how a tiny amount does all that is necessary to rearrange the molecules to make dirt magnets. The detergent manufacturers encourage overuse. All the excess detergent just pollutes freshwater after having served no purpose except to feed the mold.
3) Leave the door slightly ajar at all times for air circulation. I use the plastic cup lid from the liquid detergent as a prop.
4) I thoroughly cleaned with citric acid (Glisten for dishwasher cleaning) and though it is still somewhat stained, there is no active growth.
5) With the above precautions, I do not have to be constantly cleaning the gasket. (I predominantly use cold water washes. No need to waste water doing super hot no-clothes washings.)