So the "log" that you're looking for is the error message returned from Let's Encrypt. From the https://acme-v02.api.letsencrypt.org/acme/authz-v3/348472255457 link that you posted, it looks like one problem is
During secondary validation: DNS problem: SERVFAIL looking up A for auth-test.phs.org - the domain's nameservers may be malfunctioning; DNS problem: SERVFAIL looking up AAAA for auth-test.phs.org - the domain's nameservers may be malfunctioning
Which looks like some sort of error resolving your DNS from some parts of the world. And the DNS entry for your name looks to be a chain so there are a lot of DNS servers involved. Are you consistently getting that "secondary validation" "SERVFAIL" message? Is there anything limiting access to the authoritative DNS servers of phs.org, oktapreview.com, or awsglobalaccelerator.com that you're aware of?