Hey there @MarlaM3y and welcome to the Community! In addition to what @ScottPennwood offered, and the solutions listed from @BérangèreL, I also found this interesting perspective. I wonder if maybe it’s also a factor?
HubSpot has implemented bot filtering for email analytics, which could explain some of the discrepancies you’re seeing. Since the change, it automatically detects and excludes suspected bot activity from email performance data by default.
While it’s good because this filtering helps provide a more reliable view of human interaction with your emails, it can also negatively affect analytics.
Bot activity includes triggers from privacy filters like Apple’s Mail Privacy Protection and corporate screeners like Mimecast. The significant difference in CTR between Constant Contact (2%) and HubSpot (0.04%) could be partially attributed to HubSpot’s more aggressive bot filtering.
I did read that HubSpot has been working on improving their bot detection. The product team announced they were revamping their bot detection software, with plans to release updates. If you have bot filtering enabled in your account, you may see additional traffic being filtered from your reporting.
One way to investigate and maybe help is to check your HubSpot account’s bot filtering settings to ensure they’re configured correctly. Hope this helps a bit, too.