Ask HN: Why does Chrome not trust this trusted valid cert?

I was reading an article about how Apple is asking some of its employees to wear police-grade bodycams[0] and clicked to view the product it was referencing. Once on the manufacturer's website[1] I was wondering how much they cost so I clicked the Buy button which took me to their buy subdomain[2], but then I got a certificate error. I can't figure out why. The issue can be reproduced on another M1 MacBook Air with the same Chrome version but not on Ubuntu 20.04 with the same Chrome version. Chrome uses the system's certificate store so if the dialog says trusted - which it does - my understanding is that it should not be showing this error.

I'm on an M1 MacBook Air running Big Sur 11.4. Chrome is version 91.0.4472.114 (Official Build) (arm64).

Video: https://www.dropbox.com/s/1vrftuwtx4s1gf8/untrusted.mkv?dl=0

[0] https://www.frontpagetech.com/2021/06/28/exclusive-apple-making-employees-wear-police-grade-body-cams-in-response-to-leaks/

[1] https://www.axon.com/products/axon-body-2

[2] https://buy.axon.com/ccrz__ProductDetails?viewState=DetailView&cartID=&portalUser=&store=&cclcl=en_US&sku=74004