Smartphone Googlebots Stopped Crawling Website

Google Search Console Crawl Stats are showing the following since October Spam update (around 18th October)P

• Smartphone Googlebot - Declined to almost 0
• AdsBot Googlebot - Surging 

For context, the site also saw impression and click declines immediately after the Spam update. But that doesn't explain to me why the Smartphone Googlebot isn't crawling and especially why the AdsBot Googlebot is surging. I don't pay for ads. I rely mostly on SEO.