This is a feature of Cloudflare. By default, they obfuscate e-mail
addresses on proxied pages and then de-obfuscate them using some
JavaScript. This means that most people see the addresses eventually,
but those that don't have JS turned on never do.
The feature can be turned off from the Cloudflare dashboard by clicking
on the domain name, then visiting the "Scrape Shield" section (the last
icon from the nav menu). There you can find the "Email Address
Obfuscation" feature. It took me a few minutes to find the toggle the
first time I noticed the feature on my own domains.