Array-based consumer kits genotype a few hundred thousand preselected sites accurately and everything else badly. If you want data you can analyze yourself, you want 30x whole-genome sequencing with FASTQ, BAM/CRAM, and gVCF returned.
A FoundMyFitness report is a literature annotation layer on top of a consumer genotyping array. Here's how to audit the underlying file, rebuild the analysis yourself, and understand where array data runs out.