Getting 502 on callback

[ex0rcist]

Since few days ago, callback leads to 502, bad gateway. 1 of 10 attempts work ok, others not, Didn't touch anything, as always. Dev page says there are changes to https since november, can this be a source of problem? https://vk.com/dev/https_only

[lochnessathome]

+1, та же проблема.

[merqlove]

https://vk.com/dev/https_only?f=3.%20Требования%20к%20протоколам