A quick and happy update to this situation...
Intuit has been less than helpful over the past 6-weeks. Extremely frustrating.
However, I called in for support assistance on this issue I've been experience - the status of which has never changed up until now, as no updates seem to work. I spoke with a support rep for over an hour, and we uninstalled my 2019 TurboTax Home and Business instance.
Where things appeared to change were when attempting to pull my license from the TurboTax account to download direct from them. It couldn't be found with the license number I was provided from my purchase - TurboTax couldn't see my license. To be clear, I purchased my TurboTax license from Walmart, which in my mind shouldn't be any different from ordering from TurboTax direct. In this situation, the support rep ended up providing me a new license, as she had seen my TurboTax program functioning on my computer through screenshare; after providing me a new license, downloading direct from TurboTax, installing, and running updates, everything now seems to be working as expected. I'm moving forward with my filing!
I really don't know why this would matter, but it seems that the Walmart license simply wasn't connecting to Intuit servers appropriately. Any who may be having this same issue, it may be worth sharing this knowledge with TurboTax support and attempting this same process to get out of the never-ending rut.
Best of luck!
