VS shows projects and solutions mixed together. AFAIK there is no way to disable this and it is really annoying. VS adds projects to the recent list even when you don't open them directly. For example (and my memory on this may be fuzzy) if you add an existing project, rename a project and/or unload and load a project then VS seems to see it as an open and adds to the recent list. This makes the recent list far less useful.
In your case I haven't heard of a vproj
file but google says it is tied to video files for a program not related to VS. Therefore I'm going to assume that it might be either a temp project that VS created for some reason or perhaps you have an extension that is creating it.
I don't know what you mean by opening code files. I open source files (outside a solution/project being loaded) quite a bit without having this issue. I might recommend you take a look at the path where the project file is supposedly at to see if you can come up with a corollary.
In the interim I would recommend you use Report a Problem in VS to report the issue to MS so they can look at it, although VS 2017 is "old" and VS 2019 is now on maintenance so they will likely recommend you try replicating it in the newer version first.
Personally I pin solutions that I most often use so they appear at the top and I rarely use the recent list because of all the projects that are auto-added.