Abandoned Cart link not working on mobile (error in https)

Hello, I have an Abandoned Cart sequence set up with two links in the email - one is text hpyerlink and the other is a button.

The button works fine on mobile and desktop.  And the hyperlinked text works find on desktop.

But the hyperlinked text does not work on mobile (tried on 2 different devices, both using Android and Gmail app).  I can see that on mobile it’s sending me to a link starting with “https//” which is a typo and missing the “:”.  It should be sending me to https://

My current settings (and the ones that have always worked in the past) are:

Link Type: URL

Protocol: Other

URL: {{ event.extra.checkout_url }}

The hyperlink currently points to {{ event.extra.checkout_url }} but I’ve also tried changing the URL so it sends back to the main website just as a test.  The problem still occurs even in this test because it’s a problem with the “https” part of the URL.

I also tried changing the protocol to “https” but that did not work.

And it’s currently set up identically to an old Abandoned Cart sequence which did not have this problem.

I’ve spent hours trying stuff and I’m at my wit’s end.  What am I missing??? 

Any insight would be GREATLY appreciated!