https://jamulus.io/wiki/Compiling
I have compiled the source on my windows machine and believe a minor change is needed in the compile instructions.
Under the "Compling and building installer" topic step 5 mentions to run the powershell command with the C:\Qt\QtVersion argument. I believe this is no longer required and does not seem to make a difference when you do provide this argument.