https://en.wikipedia.org/wiki/Dogxim

For context Dogxim's 76 chromosomes came from the haploid chromosomes, 39 from the dog and 37 from the Pampas fox, the first evidence of hybridization between these two different canid species. Dogs have 78 chromosomes (39 haploid pairs), while the Pampas fox, 74 (37 haploid pairs). I was under the impression that meiosis doesn't really work well if chromosome pairs are mismatched. And this happened in nature, not in a lab. So how exactly is is possible to bridge the mismatch here?