ON CLOUD X: Running shoes pain

So I recently just bought a pair of ON runners, specifically the cloud x model. This shoe is less cushioned than my previous shoe which is the Brooks Ravenna 10. Aside from the cushioning/support, the heel to toe drop is also different from 10mm to 6mm. The part that hurts is mostly below the calf when it gets stretched (I think that’s the plantaris tendon). I’ve only used yesterday for a short 5.3km run which took 30 minutes. Today is the only time I felt the pain. Based on the ON website, the shoes will make your muscles activate so that my pronation or over pronation will become part of my running. Anyways, is any of this normal for new shoes?

If you have gone from 10mm to 6mm drop that is likely to be your issue right there. Spend some time walking around barefoot, lengthen your achilles naturally and throw away anything with a 10mm drop. Might take a few months.

Would it be a good idea to use the 6mm drop when out for casual activities? Like malls and stuff just to get use to it

No it’s not normal to get Achilles pain after running in new shoes. I would dump them immediately… Achilles tendinitis is a bitch!!
Those shoes will not make you faster no matter what the marketing department says… so if it ain’t broke don’t fix it.