Thank you for reaffirming what an ALPHA (Test) firmware is, I'm well aware and just trying to help with the testing.
This isn't mission critical, but if there was something wrong or unstable with this as an upcoming build, then I figured something should be stated so it could be discussed, addressed, or avoided for others if they DO need a stable environment /run a business/ have internet of things relying on their router.
After doing an Initialization, the 5Ghz shows down on the latest Alpha even during the SSID/Smart Connect setup, so there is not a configuration issue, as nothing has been configured yet up to that point.
Rolling back to the latest 384.8_2 version of Merlin brought the 5Ghz back, so I'm strongly suggesting there's either a flashing issue or GPL issue.