Install the GeoTrust Cross Root CA certificate and disable the existing GeoTrust self signed CA cert.
https://support.servertastic.com/rapidssl-and-geotrust-certificate-not-trusted-on-mobile-device/
https://knowledge.geotrust.com/support/knowledge-base/index?page=content&id=AR1426&actp=search&viewlocale=en_US&searchid=1283360269668
https://knowledge.rapidssl.com/support/ssl-certificate-support/index?page=content&actp=CROSSLINK&id=SO14637
Use the following SSL checkers to confirm the SSL is installed correctly.
https://knowledge.rapidssl.com/support/ssl-certificate-support/index?page=content&actp=CROSSLINK&id=SO9556
https://ssl-tools.verisign.com/#certChecker