Work for me without any issues on my Mac with Chrome and active A/d/blockPlus. And the adblocking works without interrupting the login flow.:

GET https://connect.facebook.net/en_US/fbevents.js net::ERR_BLOCKED_BY_CLIENT
GET https://px.ads.linkedin.com/attribut...Fwww.sas.se%2F net::ERR_BLOCKED_BY_CLIENT
GET https://px.ads.linkedin.com/attribut...Fwww.sas.se%2F net::ERR_BLOCKED_BY_CLIENT

From a quick analysis of the spam/bot protection it looks like SAS uses Cloudflare. And I guess they do flag some browser behavior in combination with geolocation etc...

But the SAS website is hilarious... still tries to load stuff from the test system...

Access to fetch at 'https://test.flysas.com/v2/cms-www/fragment/labels/customer-profile-common/?market=se-sv' from origin 'https://auth.flysas.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

GET https://test.flysas.com/v2/cms-www/fragment/labels/customer-profile-common/?market=se-sv net::ERR_FAILED 403 (Forbidden)