Ad Manager does not currently support creatives that use SVG tags within HTML files. Instead, you can include standalone .svg files and reference them in the HTML.
Also, Ad Manager macros are not supported within HTML files or destination URLs unless they are one of the following GDPR macros:
${GDPR}${GDPR_CONSENT_XXXX}${ADDTL_CONSENT}
Note: Transparency and Consent Framework (TCF) macros do not expand when they are implemented in the HTML of an HTML5 creative. Only Display Redirect and Custom Display creatives support expanding TCF macros via "Third-party URL" and "HTML code" fields respectively.