Hello @Chuck3, welcome to the Let's Encrypt community. 
Using the online tool Let's Debug yields these results
https://letsdebug.net/nextcloud.echogroupinc.com/1913365
ANotWorking
ERROR
nextcloud.echogroupinc.com has an A (IPv4) record (70.171.148.25) but a request to this address over port 80 did not succeed. Your web server must have at least one working IPv4 or IPv6 address.
A timeout was experienced while communicating with nextcloud.echogroupinc.com/70.171.148.25: Get "http://nextcloud.echogroupinc.com/.well-known/acme-challenge/letsdebug-test": context deadline exceeded
Trace:
@0ms: Making a request to http://nextcloud.echogroupinc.com/.well-known/acme-challenge/letsdebug-test (using initial IP 70.171.148.25)
@0ms: Dialing 70.171.148.25
@10000ms: Experienced error: context deadline exceeded
Yet from my location seem ok
$ nmap -Pn -p80,443 nextcloud.echogroupinc.com Starting Nmap 7.80 ( https://nmap.org ) at 2024-04-29 13:05 PDT
Nmap scan report for nextcloud.echogroupinc.com (70.171.148.25)
Host is up (0.070s latency).
rDNS record for 70.171.148.25: wsip-70-171-148-25.om.om.cox.net
PORT STATE SERVICE
80/tcp open http
443/tcp open https
Nmap done: 1 IP address (1 host up) scanned in 0.17 seconds
$ curl -i http://nextcloud.echogroupinc.com/.well-known/acme-challenge/sometestfile HTTP/1.1 403 Forbidden
Date: Mon, 29 Apr 2024 20:05:24 GMT
Server: Apache
Content-Length: 199
Content-Type: text/html; charset=iso-8859-1
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>403 Forbidden</title>
</head><body>
<h1>Forbidden</h1>
<p>You don't have permission to access this resource.</p>
</body></html>
From around the world I see mostly "Connection timed out" here Permanent link to this check report
Do you have some geo blocking going (or possibly your ISP or Country)?