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. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
And, you don't have any more mixed content as shown by WhyNoPadlock (apart from that link header shown by @rip).
WhyNoPadlock shows you are not redirecting http to https which you should do now your certs are working well. That's something to address in your control panel or wordpress setup. See their docs about that.
I don't see anything else related to Let's Encrypt but let us know if something comes up.