Garmin interval not working

Help me Garmin users -- I can't get my interval times to work anymore!

I go into Training Assistant - Interval Workouts - Set Time & Rest Time - then set the time, rest time & reps, hit done. The "Press Start to Begin Intervals" screen comes up. I press start and it just starts going like normal, no intervals. No beeps at the end of the set time or rest time. No interval workout at all.

I thought maybe I did something wrong, but have gone over & over it.
I've tried setting the intervals at 10 seconds and nothings happened interval wise -- it just keeps on going like I'm not using the intervals.

I've used them a lot in the past without a problem.

Any ideas??

I have the Forerunner 301.

I've gone through the manual and looked on their website & tried to find help through internet serches too.