Here’s what I heard back from support in case it helps anybody else. It’s not a bug, per se, but related to the newer HTML escaping and now requires a filter, customized to your needs:
ACF 5.10 introduced a new safer escaping system for anything rendered by ACF to prevent XSS attacks, by using WordPress’s kses system.
You can find more information on this here: https://www.advancedcustomfields.com/resources/html-escaping/
Specifically, at the bottom of that article you can see our code snippet you’ll need to add to your theme or plugin in order to allow SVGs inside your markup, as WordPress does not allow them by default.
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