I also had the exact same problem. I have LabVIEW 2020 and VIPM 2020 (Version: 20.0.2302). What solved the problem for me: After downloading the LINX Package in the VIPM Browser, I opened the VIPM Manager (Press "Open in VIPM" in the VIPM Browser). In the VIPM Manager at the bottom of the LINX-package description there was a text saying "This Package depends on these other packages: MakerHub Toolbox >= 18.104.22.168".
So I first downloaded the MakerHub Toolbox in the VIPM Browser and installed it in the VIPM Manager. After that, the installation of LINX Package (Version: 22.214.171.124) through the VIPM Manager worked perfectly.
Hope that helps you and other people out.