I try download https://developers.facebook.com/resources/FBAudienceNetwork-6.15.0.zip from different locations

from some location i retrieve file which shasum bbb103a054b42221a270e26e74a0dae3bf6401cc

From location on Hetzner network i view shasum is 81daf16fabaaa313a726ad417b0d17a1d996899b

dig from hetzner location

% host developers.facebook.com
developers.facebook.com is an alias for developers.c10r.facebook.com.
developers.c10r.facebook.com has address 157.240.251.6
developers.c10r.facebook.com has IPv6 address 2a03:2880:f083:6:face:b00c:0:2

% curl -s https://developers.facebook.com/resources/FBAudienceNetwork-6.15.0.zip | shasum
81daf16fabaaa313a726ad417b0d17a1d996899b  -

Why ? You have infrastructure desynchronization or consequences of hacking?