SSL Certificate Issue

Hi All -
Happy New Year !!!
Self-signed certificate of stackstorm expired few months ago and new one was generated using the following command:
"sudo openssl req -x509 -newkey rsa:2048 -keyout /etc/ssl/st2/st2.key -out /etc/ssl/st2/st2.crt \

-days 365 -nodes -subj "/C=US/ST=California/L=Palo Alto/O=StackStorm/OU=Information "

Although the new certificate was generated, middleware team is receiving errors after installing them. Middleware platform is 3rd party and IP address is masked. Below is the latest error

pending events=
faults=BridgeFault: Type=TEMPORARY_FAILURE, time=2020-12-29 03:10:54, message=sun.security.validator.ValidatorException: PKIX path validation failed: java.security.cert.CertPathValidatorException: Path does not chain with any of the trust anchors, throwable=javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path validation failed: java.security.cert.CertPathValidatorException: Path does not chain with any of the trust anchors

Can someone please advise on how to generate new certificate and overcome the above error