The Content-Length specifies ~3kB but only ~1kB was received at least in the case we reproduced while the network debugging proxy was attached. We also found other times the response body was empty.

I also managed to reproduce this with the CFNETWORK_DIAGNOSTICS set to 3 I can share this also if this is of any help.

Seems like I can't attach files? Is there any preferred way to share the pcap file? I uploaded it to my iCloud for now, here is the link: https://www.icloud.com/iclouddrive/0feIAezg8lTCHF18aqddPRSBA#trace