Fired Earth One coat Acrylic

I bought Fired Earth One coat Acrylic paint for outside painting as it says it is suitable for exterior. After painting the first time, the paint washed off after the first rain. I all just peeled off. I then used a primer under it and tried it again. Again when it rained the paint started to bubble and then peeled off. I am very disappointed as this product is recommended for exterior use on concrete ect. I bought a total of 6 colours that I now can't use to finnish my project.