problem with worm age and behavior

Few days ago i put up a post on problem with the egg laying behavior. I have sorted it out partly.
Turns out there was a problem with peptone. Apparently the brand of peptone (Himedia) i was using was not good enough.
I went to another worm lab repeated the whole experiment there and found out that peptone was the problem.
When i repeat the same experiment again the problem persists. Here is the problem.
I grow my worms on specifically High Growth Media (similar to NGM but has 8X peptone and 4X cholesterol).
When you bleach the worm and put them on HGM you are ideally supposed to get day 1 adults with practically no egg being laid.
This is what i get in the other worm lab which i have visited. However when i repeat the experiment in my lab i get worms which are well into
their adult hood and have laid plenty of eggs. This is messing up my chemotaxis behavior.
I have used the same brand of peptone and agar (Condo labs) as the other worm lab. I have got a fresh stock of N2 from CGC and repeated and still no luck.
I have double checked my incubator temperature, cholesterol and other components.

My questions to you guys is
Can you guys suggest what could be advancing the age of my worm?
I have a serious doubt on my OP50, is there anyway to check if your OP50 is alright?
Why is it in most behavioral experiments peptone is critical, either we are asked to increase the concentration or decrease?

Thank you

I would not be surprised if it’s your OP50. Throw it out and get a new stock.