Eggs – Why would this pastry cream have an eggy smell

I tried making a dairy free pastry cream but it came out with a strong eggy smell at the end. I may not want to use it depending how bad the smell is after is cools completely in the refrigerator.

My ingredients were

2 cups organic almond milk

1/2 cup sugar

vanilla bean + touch of vanilla extract

2-1/2 table spoons corn starch

4 egg yolks

I did it exactly as you're supposed to, whisk egg yolks with sugar until light cream colour (actually added the cornstarch with sugar to this and whisked everything together)

Boiled almond milk with vanilla, add some hot milk to egg mixture and whisk, then pour back into remaining milk. Cooking for several minutes until thicken.

Anyway, 2 of my eggs were fresh, but two were duck eggs that that were a few weeks overdue, but I
ve used them in omelette recently and they were still ok. And on cracking them open they looked and smelled ok. (I read duck eggs have thicker shell so last a bit longer than chicken eggs)

Do you think the two eggs that were a bit older was enough to make the pastry cream a strong egg smell?

Or was it maybe that I did not have enough fat content in the milk (due to the fact I used almond milk) that caused this effect?

I made pastry cream once before with whole milk and it did not have this smell.