If you pause, delete, restart a campaign, an ad group, a keyword or an ad on Google Ads, no data is collected.
No data means no impressions, and it does not affect your Quality Score.
The historical performance of paused or deleted ads and keywords will continue to affect your account history. Google Ads recommends deleting poor performing ads and keywords to improve your Quality Score.
This practice prevents ads and keywords from performing poorly in the future and further affecting your account history.
As the rest of your account accrues more performance history over time, the impact that the deleted ads and keywords have on your Quality Score will diminish.
However, after your changes, you may see a different Quality Score.
In this case, your Quality Score has been affected by other factors.
There are many factors making up the Quality Score, and Google Ads’ Quality Score is updated in real time.
The three main factors that make up the Quality Score
CTR (Click through rate).
Landing page experience.
Other important factors
The relevance of each keyword to its ad group.
Your historical Google Ads account performance.
The user’s device.
Your ad’s geographic performance.
Landing page loading time.
Quality Score updates
The CTR’s Quality Score is updated daily for most keywords, but not always at the same time.
The time you restarted your keyword may also impact your Quality Score.
The Google Ads Relevancy’s Quality Score is updated once per week.
The Google Ads’ Quality Score algorithm is updated about once per month.
Extract from my Book ‘Making Google Ads Work’.