MAC Web Sockets Expired DST Root CA X3

[webprofusion]

You could try installing the ISRG Root X1 certificate onto the dev machine:

Let's Encrypt DST Root CA X3 expiry Sept 30th 2021 | Certify The Web Docs

Alternatively, change Certificate Authority: Certificate Authorities | Certify The Web Docs

Note that Certify The Web has a built in set of certificate export tasks (under Tasks), such as Deploy to Generic Server, so you don’t usually have to use other tools to convert certificates.