Google was asked in what case will Google not select an exact match of a keyword versus a close matching keyword in the campaign. PPCGreg who asked this on Twitter said he is "seeing a growing number of instances where this is the case."
Ginny Marvin of Google under the AdsLiasion account responded that in all the cases where advertisers complained about this, it came out to be around keyword eligibility issues. Ginny wrote on Twitter "an exact match keyword that's identical to a query will be preferred regardless of AdRank -- as long as it's eligible to match. Eligibility is key." She added that Google has some exceptions documented including a campaign is limited by budget and/or one of your keywords isn’t eligible to trigger an ad. Ginny added for example "it won't be eligible if the Exact match is outside of the geo target or the Exact campaign was paused part of the day."
Ginny Marvin did add that "since the February update," where Google said phrase match will expand to cover additional broad match modifier traffic, "the situations the team has reviewed have all been attributed to eligibility." So there does not seem to be a bug where Google is ignoring the exact match and opting the other match types.
If you have an exact match keyword that is identical to the search term, this keyword is preferred for triggering an ad, Google said. Google added that "this is true even if there are other keywords in your account that are similar to the search term." This is the example Google gave:
Let's say the search term is plumber course and your account includes the exact match keywords [plumber course] and [plumber training course] as well as the phrase match keyword “plumber course”. In this example, the exact match keyword [plumber course] is preferred because it’s exact match and identical to the search term plumber course.
Here are the relevant tweets for this story:
Hi Greg, An exact match keyword that's identical to a query will be preferred regardless of AdRank -- as long as it's eligible to match. Eligibility is key.
— AdsLiaison (@adsliaison) June 8, 2021
On that same help page see the Exceptions section: https://t.co/JEILuKAfvH
For example...
if you have examples to share, happy to pass along for a closer look -- and thanks for the question.
— AdsLiaison (@adsliaison) June 8, 2021
So I guess if you see examples of Google failing at this, let Ginny know on Twitter.
Forum discussion at Twitter.