Save as SVG and style using Presentation Attributes styling

I have several Illustrator files that I would like to have as svgs. I have been using Save As .. to save them as svgs and NOT Export as svg. Up until recently the svg that has been created by this workflow had been exactly what I wanted.

This is an example here;-

<?xml version="1.0" encoding="utf-8"?>

<!-- Generator: Adobe Illustrator 21.1.0, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->

<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"

viewBox="0 0 512 512" enable-background="new 0 0 512 512" xml:space="preserve">

<path fill="none" stroke="#000000" stroke-width="30" stroke-linecap="round" d="M368,245.6c0-61.9-50.1-112-112-112

c-61.9,0-112,50.1-112,112v133.7"/>

<line fill="none" stroke="#000000" stroke-width="30" stroke-linecap="round" x1="368" y1="379.3" x2="368" y2="245.6"/>

</svg>

Having come to these files I am now finding that doing Save As .. on the exact same file (with no changes) creates this;-

<?xml version="1.0" encoding="utf-8"?>

<!-- Generator: Adobe Illustrator 21.1.0, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->

<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"

viewBox="0 0 512 512" style="enable-background:new 0 0 512 512;" xml:space="preserve">

<style type="text/css">

.Arched_x0020_Green{fill:url(#SVGID_1_);stroke:#FFFFFF;stroke-width:0.25;stroke-miterlimit:1;}

.st0{fill:none;stroke:#000000;stroke-width:30;stroke-linecap:round;}

</style>

<linearGradient id="SVGID_1_" gradientUnits="userSpaceOnUse" x1="0" y1="512" x2="0.7071" y2="511.2929">

<stop  offset="0" style="stop-color:#339A2A"/>

<stop  offset="0.9831" style="stop-color:#121E0D"/>

</linearGradient>

<path class="st0" d="M368,245.6c0-61.9-50.1-112-112-112c-61.9,0-112,50.1-112,112v133.7"/>

<line class="st0" x1="368" y1="379.3" x2="368" y2="245.6"/>

</svg>

I have not changed the original file and have not changed my workflow. I have used Save As.. > .svg for both of the above. It's possible that I have changed some preference setting in Illustrator somewhere but I have no idea what.

Please can someone help me? I would like to have ;-

fill="none" stroke="#000000" stroke-width="30" stroke-linecap="round"

instead of the css styling. Also I have no idea where the gradient is coming from. I have not added that to the ai file