Cannot install plugins or themes "error setting certificate verify locations"

Please assist with the following error. I have read through numerous forums concerning the same issue with no resolve.

When attempting to install a plugin or theme, the following error occurs;

“Download failed. error setting certificate verify locations: CAfile: /public_html/wp-includes/certificates/ca-bundle.crt CApath: none”

The response received from my hosting provider was:
“As per the update from our senior administrators, this is not an issue with our server. We have already done the required changes on the domain. The issue seems to be related to WordPress. For that, you may contact the WordPress support or a developer for further clarifications.” and;

“We have already analyzed the logs and confirmed that there are no modsecurity errors triggered for the domain : boxsmartmedia.co.za. The issue is not with our shared hosting. There seems to some connection issues to WordPress servers from our end. You may contact a developer and make the required changes in the site files as mentioned in the URL : https://wordpress.org/support/topic/ssl-certificate-problem-unable-to-get-local-issuer-certificate-2
We have already confirmed with our seniors that this is not the case with our server. Hence, please refer the URL and make the corrections from your end itself. “

The suggested code “add_filter( ‘https_local_ssl_verify’, ‘__return_false’ );” does not make a difference. I have exhausted all options with no resolve.

I have also uploaded a new CA-bundle from WordPress.org again, no resolve.

I would greatly appreciate any assistance.