Post-wash odor is usually caused by moisture, detergent buildup and slow drying rather than by a mysteriously bad detergent.
Slow drying is the main problem
A wet towel left folded or sitting in a hamper stays damp for too long. Hang it fully open and let it dry as quickly as possible after use.
More detergent is not always cleaner
Too much detergent or fabric softener can remain in the fibers, trap odors and reduce absorbency. Follow the recommended dose and adjust for water hardness.
Do not overload the washer
An overloaded washer cannot rinse towels effectively. Leave enough room for water and detergent to move through the fabric.
Check the washing machine itself
If many types of laundry smell, the source may be the washer gasket, detergent drawer, filter or drain system. Clean accessible parts and use the manufacturer’s maintenance cycle when recommended.
Bottom line
Keep the solution simple: start with the most likely cause, change one factor at a time, and observe the result. That makes it much easier to identify what actually works in your situation.