Since years now the default platform to open a project on Windows has been Windows 64bit in Unity.
(For example if you delete your Library folder and launch Unity with Current Build Target this is what will be selected.)
However if you select Windows in UnityHub it will set the platform to Windows 32bit.
This is an issue because in Unity doing this will cause a full reimport and/or pollute the Cache Server with Gigabytes of unwanted content.
This could be fixed by launching Windows 64bit when selected Windows from UnityHub - or alternatively allow for both Windows 32bit and Windows 64bit to be selected.