Ya… I looked at OP but I didn’t think about that. I’ve had similar issues with other things, not just ACF. Nothing like the need to load a font that has no useful purpose to make a site run.
The ACF CSS files have the dashicon CSS as a dependency. If not included the the ACF CSS will not load.
Are you calling acf_form_head() on every page or are you calling conditionally. If you are calling it conditionally then you could de-register the style when not calling acf_form_head().