You might be right about the number of installs, but when I reinstalled I did not need to enter a license code or register, and so I think the program recognized the existing license on my computer.
I too was able to update successfully 1 or 2 times before it started failing to update.
I retried the manual update again (https://ttlc.intuit.com/turbotax-support/en-us/help-article/update-products/manually-update-turbotax...), but it didn't help.
