I'm hosted on CloudWays

You should exclude cookies from varnish cache via the Cloudways platform.

Navigate to Application Management > Application Settings > Varnish Settings.

Add the following cookies in there

COOKIES

utm_campaign
utm_source
utm_term
utm_medium
utm_content
gclid
first_utm_campaign
first_utm_source
first_utm_term
first_utm_medium
first_utm_content
handl_original_ref
handl_landing_page
handl_ip
handl_ref
handl_url
organic_source
gaclientid
//and all the custom parameters created by you