Yes, same symptoms but with other 5xx errors. The support response: "It's not us, move along!" Especially since OVH sometimes displays an error page specific to their theme "hosting in maintenance" from time to time (in my case), and they are currently unable to see where it comes from (someone reopened the "502" ticket to try to see where it comes from), worse, they shift the blame onto us!
OVH, it's high time to investigate further.
My 502 thread: Erreur 502 Bad Gateway, pas d'accès au site depuis 8 heures (cluster024) - numéro 31
My 504 thread: 502 puis maintenant c'est 504 Gateway Time-out, où va t'on chez OVH? - #5 par SteveT