Just heard back more from my hosting provider. They’ve said:
“Unfortunately the plugin’s [EBS + EBS Pro] issues with hitting our cache have been present since at least before September as we notified you of the resource usage in #97099.
We can try to enable the easy-bootstrap-shortcode-pro and then disable all of the cookies using a plugin, but that would be a band-aid fix and may also have a negative effect on some of the functionality of your site. It’s possible that the PRO version of the plugin introduced these issues; I’d recommend contacting the plugin developers if they have a patch or solution that doesn’t require the PHP sessions from being initiated.”
I hope this helps with describing the issue.