Turbo Tax Deluxe 2021 Won't Install

Install exe downloaded from Amazon extracts but won't install. I've tried everything I could find on TT support and via Google searches, to no avail. Details:

- Windows 10 Pro, version 21H2, build [removed], 16 GB RAM, 230 GB disk space available, GB fiber Internet connection

- Anti-virus and firewall disabled (Windows Security)

- Ran sfc and dism - no errors found or fixed

- Ran anti-virus full scan - no threats found

- Ran downloaded exe as admin (no other apps running), files were extracted, C:\ProgramData\Intuit\TurboTax\MSI\TY21 directory and 20211227_TTINSTALLER.log file created (shows no other instance; locking now), then nothing

- Ran extracted setup.exe from %TEMP% as admin, got the standard UAC prompt, then nothing

- Ran extracted TurboTax 2021 Installer.exe from %TEMP% as admin, got the standard UAC prompt, then nothing

- Tried selective startup with all non-Microsoft services disabled, repeated prior install attempts, additional files created in MSI\TY21 directory (no errors recorded), just UAC prompt, then nothing.

- Added download, setup, and installer exes as exclusions in anti-virus and firewall settings, tried again, no change in results.

- Tried all the above with a new download via Chrome, same results.

- Tried all the above with a new download via Edge, same results.

- No errors in Event Viewer appear to be related to the install attempts.

- Have had no problems installing any other software on my PC.

Hoped to contact support by phone, but web page says they're closed - open 5-5 Pacific, which is 7-7 my time. It was about 2:00 on a Monday when I checked, so I feel like I just set a $50 bill on fire.