Hello,
You need to open your SVG icons file with some editor like Sublime Text or default system text editor and add width=”31″ height=”40″ attributes to your <svg>
tag like it is shown: http://prntscr.com/m4n0qw
Then you will need to re-upload your icons in WordPress Dashboard.
Also the problem is caused by SVG itself: some of your SVG images have styles that are applied to the whole page. As a result, the styles of one SVG icon influence the other. In order to solve this, you need to insert inline styles without classes.
You can open your SVG image in any text editor and manually change styles to inline like is shown on this screenshot https://prnt.sc/loz0mw.
If you have any questions please feel free to contact us.
Best Regards