UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36

Steps to reproduce the problem:
I am using a link in google sites to produce an email  to subscribe and unsubscribe to google groups.  So link is mailto:jh.parents+unsubscribe@stbobcats.net which produces the link https://mail.google.com/mail/u/0/?view=cm&fs=1&tf=1&to=jh.parents+unsubscribe@stbobcats.net, however in the To: field of the email it reads as jh.parents unsubscribe@stbobcats.net  So my + sign is getting converted into a space.

This appears to be a chrome issue.  Firefox produces the email properly, so do phones, outlook etc...  You have to have a handler for mailto to work in Chrome and I have tried every extension available in the chrome store.  Same problem occurs whether I try to generate it in yahoo mail or gmail in chrome but both work in other browsers.  Tried all of the MailTo extension addons for Chrome and they all produce the same results.  This featured worked in late 2016 when I first implemented it.

What is the expected behavior?
I should get jh.parents+unsubscribe@stbobcats.net in the To field

What went wrong?
I get jh.parents unsubscribe@stbobcats.net so the + is being converted into a space.

Did this work before? Yes Worked around October 2016.  That's when I originally created the feature.

Chrome version: 58.0.3029.110  Channel: stable
OS Version: 10.0
Flash Version: