Everything was going great. You had your Google Ad campaign set to Max Conversions Bid Strategy, and you were getting a decent volume of leads at a solid cost per conversion.
Seemingly out of nowhere, your campaign's performance starts to tank. Struggling to produce even one conversion in the same time period you normally would generate several.
What happened!? What should you do!? Should you change bid strategies!?
First of all, don't panic. Making huge drastic changes to your campaign right now might just make it worse.
The first step is to view your search terms report for the entire life of the campaign. Sort by cost and see if there are any search terms that are driving a high cost but zero conversions.
If there are any that have a higher cost than your campaign's average cost per conversion, add them as a negative. I like to use either phrase match or exact match types for negative keywords so I don't accidentally restrict any search terms that are converting.
You'll want then to sort your search terms report by cost per conversion. Are there any with a really high cost per conversion, a lot higher than your campaign's average cost per conversion? If so, consider adding them also as negative keywords.
Do the same thing across the following dimensions; demographics, location, ad schedule and device. If you haven't set up your location targeting and ad schedule in a granular fashion, you should do that now.
If there are any dimensions that are driving up a high cost but not converting, try excluding them from the campaign.
I would consider creating a Google Ad Experiment with 50% of the budget to test Max Clicks Bid Strategy or Manual CPC Bid Strategy. I've had some campaigns that converted better with Max Clicks or Manual CPC for one reason or another.
It also helps to set up ad groups in a granular fashion based on keyword themes instead of grouping them all in one ad group. This allows you to spot trends and exclude any keyword themes that aren't converting as well.
As you can see, there's a lot you can do to optimize a Google Ad campaign that is using Maximize Conversions Bid Strategy.