In order for an SSL/TLS Certificate yo work properly, so that your website content would be shown in all devices and browsers using HTTPS, without any problems, you need to use an SSL Certificate Trust Chain instead of a simple certificate.
To create a certificate trust chain, you will need an Intermediate Certificate as well as a Root Certificate. The Root Certificate and the intermediate certificate are provided to you by your SSL/TLS certificate provider. In case you do not have access to these files, you can simply download the from the company's website that issued your certificate.
How to Create the SSL Certificate Trust Chain
You can simply use a text editor like vim or notepad to create the trust chain file. You then need to use the following commands to create a file including the website certificate, root certificate, and intermediate certificate.
(Your Primary SSL certificate: yourwebsite.crt)
(Your Intermediate certificate: INTERMEDIATE.crt)
(Your Root certificate: Root.crt)