I'm in a situation where I'm not particularly sure what's happening and any help would be appreciated.

I have auto-tagging enabled in Google Ads, and recently started adding UTMs. After doing so, the session medium in GA4 shows that cpc sessions decreased while (not set) went up.

I can confirm that the UTMs in the landing URL after an ad click. I have them set at the account level as utm_source=google&utm_medium=cpc&utm_campaign={_campaignname}, with _campaignname defined for every campaign. Am I missing something? It's like adding the UTM tags is somehow reclassifying what the auto-tagging did, despite auto-tagging taking attribution preference.