The ad CTR is great today, but leads are low. How do I check the landing page and UTM?

One ad group had a very high CTR today, but lead form submissions were low. My colleague in ad operations wanted to swap out the creative, but I decided to check GA4, UTM, landing page speed, and form errors first. It turned out that after the third-party chat widget loaded on mobile, the button on the first screen had a delay before it became clickable, and some users got no response when they…