Lead is in our soil, and used to be in some agricultural products (banned for years now) but it is persistent, and therefor may make its way into some of our foods. It is present in our soil, air and water.

I am guessing here, but if the product is manufactured in Europe where the labeling rules are stricter, they may be copying what comes to them with the imported product or ingredients.

One cannot entirely avoid lead, because it is found in everything from salt to root vegetables to fruits to greens, but eating a diet high in iron, calcium and Vitamin C helps the lead pass through the digestive system without being absorbed by the body.

Here is an article I found helpful:
https://dph.illinois.gov/content/dam/soi/en/web/idph/files/publications/get-theleadout-activitiesto-reduce-lead-exposure-042016.pdf