Funny situation, and I'm not sure if this is my fault or Google's.
I have a domain, example.com, which has 2 subdomains: main.example.com, and spf.example.com. For main.example.com domain, my TXT record used to be defined as: v=spf1 redirect=example.com with relevant TXT for example.com defined.
For various reasons, I decided to create "main" TXT SPF for spf.example.com, and redirect there. Please note that SOA and NS exists only for example.com. I changed main.example.com TXT to read v=spf1 redirect=spf.example.com and Google (according to DMARC report) does not see the SPF record anymore. Yahoo and Microsoft do.
So I run a second test: created backup.example.com, sent a few email without TXT SPF defined, DMARC report from all of Yahoo, MS and Google reflects that there's no TXT SPF. Defined TXT as v=spf1 redirect=spf.example.com and bam, MS and Yahoo noticed that, while Google still did not.
Any explanation except for "Google mail software sucks"?