CDN errors trying to download snap "core" from channel "stable"

For what it’s worth, I’ve got this error trying to download core twice:

error: cannot perform the following tasks:
- Download snap "core" (8689) from channel "stable" (received an unexpected http response code (502) when trying to download
##[error]Process completed with exit code 1.

Original log:

In the short term, I’m trying to disable the use of the CDN with the environment variable SNAPPY_STORE_NO_CDN=1.