The timer does not move

the weshing machine stays on the regular soil cycle and never moves to the rinse cycle unless i manually move the timer to the rinse cycle

A model number may help others help you.

Many units have a thermal hold, they wait for the water to be heated to a set point before continuing the cycle. Check the heater and thermostat with a meter.

If the unit has a cycle type that does not heat the water, try that.
If it now runs OK then a heating problem is your most likely cause.