Your DKIM and Return-Path still say acems1.com
Until you set up a sending domain, ActiveCampaign signs every campaign with its own domain, something like acems1.com, and routes bounces through an ActiveCampaign-owned Return-Path domain. SPF and DKIM both pass, but neither aligns with your From domain, and Gmail shows "via acems1.com" next to your sender name. Since the February 2024 Google and Yahoo rules, bulk senders need DMARC-aligned mail, and unaligned sends build reputation for ActiveCampaign's domain instead of yours. Set up your sending domain under Settings > Advanced; once DKIM signs with your domain, the via label disappears.