Autocomplete on Newsletter form populates email address on all fields

Site URL: https://mayadeane.com

We just soft launched this site. It has a simple "sign up for alerts" form on the home page. One person testing it said that autocomplete put her email address in all of the fields, apparently including the first and last name fields. I can't repeat the error and am trying to get her to send a video of it happening.

I have no idea what could cause this on Squarespace's end. This is indeed my first Squarespace site - though I am a web developer with 8 years experience in HTML / JS / CSS and backend languages.

Is there anything I don't understand about Squarespace that could cause issues with autocomplete? The HTML looks like it should be working fine, and I wonder if it's not an issue with that one tester's browser settings. But that would also be strange, and I know her to be a highly tech savvy person.

Thank you for any help!!

~Eileen

UPDATE:

The tester is using a Samsung phone, and it only happens when she opens the link via her facebook messenger app. If she uses the mobile chrome browser directly, it doesn't happen. 

So it's got something to do with the browser opened via facebook messenger.

Also - there's another form on a different page where this issue does not occur. It only happens on the newsletter form. The newsletter form opens in a lightbox modal, so I suspect that's a factor here too.

Although websites can and do provide auto-complete I'm not aware of SS having ac in their forms. Auto-complete is a common feature of browsers especially for email, name, address, and phone.

Ac is not particularly smart in the browser and it is possible to get undesired results. It can mean that the ac values need to be cleared or cleaned up, if the browser supports that feature.

Thanks creedon - I ended up sending it to Squarespace support and they pretty much said it's got to be the tester's browser and won't investigate it further unless she does probably an hour's worth of debugging on her phone to rule out various possibilities. I don't feel comfortable asking that of her since she just checked it out as a quick friendly thing, so it's probably just going to stay as is. But I do doubt many users at all will be affected.