@Vscpp Welcome to the community
You are another one affected by a Palo Alto Networks brand firewall. They changed a default setting in their gear earlier this year and we have seen this regularly.
You should talk to your network admins and have them change the Application Rule for "ACME protocol".
As a test, the below request should reply with a 404 Not Found. Instead, it gets the "reset by peer" error. In your case, you must use the -A as shown as that is the user-agent used by Let's Encrypt servers. You can use this sample curl and URL to test the setting was changed properly
curl -I q.ezecom.com.kh/.well-known/acme-challenge/SampleToken -A "Mozilla/5.0 (compatible; Let's Encrypt validation server; +https://www.letsencrypt.org)"
curl: (56) Recv failure: Connection reset by peer
Should get this, even with that -A value, instead
curl -I q.ezecom.com.kh/.well-known/acme-challenge/SampleToken
HTTP/1.1 404 Not Found
Server: nginx/1.23.1
Date: Tue, 13 Sep 2022 14:13:40 GMT