Sendgrid bounces for apple login private relay accounts

We have configured multiple ESPs, which works for private relay emails. Recently sendgrid started bouncing for my testing private relay email ( aqdi34p4ti@privaterelay.appleid.com -- smtp;550 5.1.1 Relay not allowed ) even though we have registered both - domains and communication emails (as described in Configure Private Email Relay Service ).
Is it possible to check logs what's going on? Or did something changed?
I am having the same issue, and would appreciate some insights too. Thanks!
Sendgrid bounces for apple login private relay accounts
 
 
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