I have a project on the Firebase, which contains both iOS and Android apps, which are tracking as expected in the Firebase and Analytics.

My next goal was to set up an ad campaign on the Google Ads website. I have linked both Firebase and Analytics accounts with my Google Ads account. Android is doing well and right after the linking conversions appeared and ad campaigns are running successfully. But with the iOS app I have problems - first_open conversion is not showing anywhere in the Google Ads console, and if I try to reimport conversions it shows, that I've already imported all of them. Because of that, I am not able to run iOS ad campaigns which are quite disappointing.

I saw a lot of requests like that on the web, but on all of them "Google GOLD Experts" are saying to recheck linking, which makes no sense.

Does anyone was able to fix this bug? I have found that MAYBE we should use Google Tag Manager and connect it with the Google Ads to track iOS conversations.

Having a Website www.example.com and a WebApp myapp.example.com with the following configuration:

• Both the Website and the WebApp use the Firebase JS SDK for tracking analytics events using the same Firebase config (= they track in the same linked Web+App GA Property)
• The Website contains the landing page where people from Google Ads land
• The Website has a regular <a ...> link to the WebApp (myapp.example.com)
• Conversion events are set up in the WebApp for tracking
• The GA Property is correctly linked to Google Ads and Conversions are imported correctly in Google Ads

The user flow this issue is about is: Google Ad -> Landing page on www.example.com -> navigates to myapp.example.com -> conversion on myapp.example.com

The situation is now that tracking works from both domains and conversions are also tracked in GA, meaning: if I view the "Conversions" Report, I see the conversions for these events. Also if I set the attribution selector for a specific event to "Google Ads preferred last click" , I can see that some conversions are attributed to the Google Ads campaigns.

But Google Ads does not recognize these conversions and shows the message "No recently tracked conversions" for these events even after waiting several days.

When switching the Attribution model in GA to "Cross-channel last click" for the conversion, the medium cpc (as it is displayed with the attribution model "Google Ads preferred last click" applied) is replaced by referral and campaign information is no longer available.

So I guess this is where the conversion tracking for Google Ads breaks and that's the reason why Google Ads does not detect the conversions correctly: because they happen on the "referral" from www.example.com and not directly from the initial Google Ads referral - even though Google Analytics can attribute the conversions correctly when setting the attribution model as mentioned above.

For regular GA using analytics.js, as far as I know there is a specific setup possible using the options {'allowLinker': true} and ga('linker:autoLink', ['example-2.com'] ); (as described in this documentation).

But for Firebase JS SDK, I could not manage to find any information how to setup cross-domain (even though it's only about subdomains in this case) tracking correctly so Google Ads still attributes the conversions correctly to the domains.

What needs to be done with this setup so that conversion tracking in Google Ads works correctly with the given setup using Firebase JS SDK?

When importing events from Firebase analytics to Google Ads, I am seeing all other events except for first_open for iOS platform, it's showing for Android though. What could be wrong?