From your logs, can you see how long exactly the request takes before the connection closes? If it happens each time after 60 seconds there might still be something with your socket timeout settings.
Note that there is test case timeout and socket timeout. I referred to the latter. See
https://support.smartbear.com/readyapi/docs/functional/ui/case.html#options (The duration (ms) of a connection socket. The empty value or 0 sets the timeout to 1 minute.)
Or your rest service (or any other downstream service) has a timeout set whichafter it closes down. But if you say it consistently fails for ReadyAPI but works for Postmen than this cannot be the case.
Or perhaps another instance of readyAPI is already running on your machine? I know you can open ReadyAPI 2 times, but that does cause some instabilities I noticed... It could be a reason for the exotic "An established connection was aborted by the software in your host machine." Not tested it, but just trying to get some clues...
