Hello @neonguyen, welcome to the Let's Encrypt community. 
The Android version is important in assisting.
Here is a reference on [Long (default) and Short (alternate) Certificate Chains Explained ](Long (default) and Short (alternate) Certificate Chains Explained, as Androids has Chain of Trust - Let's Encrypt Root Certificate that is signed by the Expired Cross-signed by DST Root CA X3. So Long Chains are often need with support for Androids.
Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. crt.sh | example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
My domain is:
I ran this command:
It produced this output:
My web server is (include version):
The operating system my web server runs on is (include version):
My hosting provider, if applicable, is:
I can login to a root shell on my machine (yes or no, or I don't know):
I'm using a control panel to manage my site (no, or provide the name and version of the control panel):
The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot):
Thank you for assisting us in helping YOU!