Had this problem one year ago using VS 2017 and up-to-date software (along with the rest of the team, VS 2019 wasn't stable yet don't know if it's fixed there).
First I'd recommend upgrading to VS 2019, because you're currently missing ~1.5 years' worth of improvements in C# and F# tooling (core development for VS 2017 stopped well before the VS 15.9 release to stabilize it). If it still reproduces, then please use the Report a Problem tool to file an issue. The team who builds C# tooling would be interested in fixing that kind of problem.
Oh for sure - I'm not using .NET/VS anymore different clients and all, and I think the team stripped out the F# tests out of the solution - just saying it couldn't have been the thing fixed 3 years ago.
