This might be a pile-up area, Alice has about 20 similar-sized matches in the same area. Alice is now on AncestryDNA too, if I look for your dad on her match list how would his name appear? It could be that Ancestry's matching algorithm eliminated the match as a pile-up and that would be useful info (even though we may choose not to believe it). Ancestry has eliminated a few of my valid matches. On your dad's list, look for Alice as "AAVautrain".