In 2019 I had to pay tax on some RSU money that I hadn't received. This year the RSU was granted and it seems I'm being taxed on the whole amt again?

[mbdowty]

In 2019 despite the fact that the RSU hadn't vested I was forced to pay tax on a portion of it because of my age (56) it was considered somewhat under my control.  That always seemed wrong, but whatever.  
This year that money did indeed vest, but it seems like the whole amount is being taxed.  How do I account for the fact that some portion of this was already taxed in 2019 filings?  It is showing as income on my W2.

[TomD8]

Check with your employer's payroll department.  Companies can and sometimes do pay dividend equivalent payouts for unvested RSUs. Unlike actual dividends, the dividends on restricted stock will be reported on your W-2 as wages, unless you made a Section 83(b) election.  This web reference has a more detailed explanation:

https://www.naspp.com/Blog/May-2019/Dividends-and-Equivalents-Ten-Things-to-Know#:~:text=Since%20div....

Perhaps you paid 2019 tax on a dividend equivalent payout, not on the RSU's themselves.