If an SVG uses things like gradients, clip paths, masks, classes etc then these must have unique names/ids if they are show on a page with other similar SVG. As would be the case with HTML for example
This can be encountered when SVGs don't display correctly - especially ones using clippaths - when show on a page with other similar SVGs, but display OK when shown alone.
They will also fail accessibility checks (WCAG 2.1 (A), WCAG 2.0 (A)).