The feature for highlights in the vignetting tool is currently not working. I ahve the lates update installed as well. IS there a fix or pending update to resolve this issue. I noticed from otehr posts done years ago that this has been an issue in prior release cersions.
Please post your System Information as Lightroom Classic (LrC) reports it. In LrC click on Help, then System Info, then Copy. Paste that information into a reply. Please present all information from first line down to and including Plug-in Info. Info after Plug-in info can be cut as that is just so much dead space to us non-Techs.