Secured server calls started 'Error #2032: Stream Error' from AIR 27+

Test environment:

Adobe AIR: 26, 28

macOS: 10.11.6

We have multiple application running on Windows and macOS with AIR SDKs. All service calls happens to our secure servers (https). We had no problem until AIR 26 on macOS.

We know that App Transport Security being introduced recently with effects from AIR SDK 27+ on macOS.

With the use of AIR SDK 28.0, we starts getting following error against our calls to https servers:

Error: [IOErrorEvent type="ioError" bubbles=false cancelable=false eventPhase=2 text="Error #2032: Stream Error. URL: https://[censored]/details.nsf" errorID=2032]. URL: https://[censored]/details.nsf

The above problem is valid only on macOS, in Windows we have no problem with SDK 28.0 to connecting the servers.

Since the above errors we decided to renew certificates to our servers. Even after the new certificate being applied, we continue getting same IOError with the usage of AIR SDK 28.0 on macOS.

Second part of our problem is, we tried to degrade the SDK to use 26.0, and we've being reported with following notification on macOS (this notification do not comes on Windows, and we have no problem with our connection on Windows):

In short, we are now facing two questions:

1. Why AIR 28.0 throwing IOError even the calls made to https servers?

2. Why we're having untrusted issuer prompt on SDK < 27?

Any help would be very appreciated.

Thanks!