Newsletter Signup Form Redirecting to Dead Link

Hi there,

First of all, thank you in advance for giving attention to my issue.

I am using WP version 4.9.8, with Thesis theme 2.6.4.

This issue is difficult for me to reproduce consistently, as it seems to be intermittent, at least on my Mac. I am unable to reproduce it at all using Safari or Firefox, but can reproduce it intermittently on Chrome. I have received at least three reports from others who have experienced it, at least one of whom was using an iPhone. It is happening on two different signup buttons: on my home page, and on my blog sidebar.

I spoke with a Constant Contact technician, who instructed me to rebuild my signup button (which I did) and then redirected me to WP support, saying that something in my WP settings is causing the link to redirect, possibly attempting to track the traffic via the following link:

http://go.trafficrouter.io/?res=nm&original=http%3A%2F%2Fconstant-contact.evyy.net%2Fc%2F27795%2F211045%2F3411%3FsubId1%3Djkkffe72nb02jez305xhi%26u%3Dhttps%253A%252F%252Fvisitor.r20.constantcontact.com%252Fd.jsp%253Fllr%253D9wfpgl8ab%2526p%253Doi%2526m%253D1128878544602%2526sit%253Dcmx7za9lb%2526f%253D2a712234-e740-4d5a-b292-26cf2f03b750&dst=&brid=&dstsig=

I checked my plugins and can see no reason there for the traffic from the newsletter form to be tracked. I tried searching online for a solution but could find no leads whatsoever, except that when I search for the domain it is being redirected to (go.trafficrouter.io) I am told that it is used by HTTPS everywhere:
https://www.eff.org/https-everywhere/atlas/domains/trafficrouter.io.html

I think that is all I have to share at this point.

Thanks again.

The page I need help with: [log in to see the link]