I have reviewed all of the Quicken announcements (
https://www.quicken.com/press/quicken-strengthens-investment-features), help documentation (
https://help.quicken.com/display/WIN/About+restricted+stock+units), and release notes (
https://www.quicken.com/support/quicken-windows-release-notes), and there is nothing in there that says RSU support is only for Premier and higher. It is offered as a feature for "Investment" customers, and Deluxe very definitely supports Investments. The only aspect of RSU support limited to Premier customers is called out in the release noted for R45.7: "Quicken Premier and Quicken H&B now provide an option to specify units instead of percentage or gradient when adding an RSU Grant."
The original September press announcement linked above (at
https://www.quicken.com/press/quicken-strengthens-investment-features) also emphasizes the value of the new features and makes no indication that they are for Premier & H&B only - although it DOES call out that restriction for real-time quotes, indicating that the restriction does not apply to RSU support.
In other discussions, it is stated that RSU support was limited to Premier & higher in R44.20, but there is nothing in the release notes about this. The R44.20 release notes do call out "Created the Other Investments option as part of the Add Account feature. The Other Investments option can be used for setting up Stock Options, RSUs, Investment Partnerships, and other manual investments" with no limitation on the Quicken version this applies to, just as the R43.14 release notes trumpeted "Added Restricted Stock Unit (RSU) tracking in investment accounts, accessed from ‘Enter Transactions’" without limiting it to Premier & H&B.
RSU support was announced and marketed as a feature of Quicken Deluxe that I and many other customers have paid for. Quicken promoted it to me when it became available. Please get it working again ASAP.