Can google ads screw up?

Question

Google Ads

Good morning, there is Google advertising, there was a site #1 advertising gave 15-20 requests per day. Then the site moved to Bitrix, this is site #2. There were almost no applications. Now the site is #3 on wordpress, with a direct conversion of the site into sales of 6%. For the flower delivery market, the norms, but Google advertising pours traffic, but there are no applications. It is worth the strategy of maximum conversions. I dug deeper and found out that Google ads had targets from old sites. Question: can google ads fail because of the old goals that are incorrect for the new site? I don't have any other options for why it doesn't work.