Rider won't run my unit test after a while (and I have to clear my cache)

Unfortunately, it's impossible to discover unit tests in some of your projects. :(
Below you can find the error details for each project.

Project: PROJECT_NAME (PATH_TO_MY_DLL)
  Exception occurred during exploration.
    JetBrains.ReSharper.UnitTestFramework.Common.Exceptions.ElementDoesNotExistException: Could not load element by id
       at JetBrains.ReSharper.UnitTestFramework.Persistence.LevelDb.Query.QueryResult.GetEnumerator()+MoveNext()
       at System.Linq.Enumerable.ToDictionary[TSource,TKey](IEnumerable`1 source, Func`2 keySelector, IEqualityComparer`1 comparer)
       at JetBrains.ReSharper.UnitTestFramework.Exploration.UnitTestDiscoveryTransaction.PrepareForCommit(IUnitTestTransaction tx)
       at JetBrains.ReSharper.UnitTestFramework.Persistence.LevelDb.UnitTestTransaction.CommitCore()
       at JetBrains.ReSharper.UnitTestFramework.Persistence.LevelDb.UnitTestTransaction.Commit()
       at System.Threading.Tasks.Task`1.InnerInvoke()
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
    --- End of stack trace from previous location ---
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
    --- End of stack trace from previous location ---
       at JetBrains.ReSharper.UnitTestFramework.Exploration.UnitTestDiscoveryTransaction.CommitAsync(CancellationToken ct)
       at JetBrains.ReSharper.UnitTestFramework.Exploration.Artifacts.UnitTestArtifactExplorationRunner.ApplyExplorationResults(IExplorationResult[] results, IUnitTestDiscoveryTransaction tx, Boolean supportedByProvider, CancellationToken token)
       at JetBrains.ReSharper.UnitTestFramework.Exploration.Artifacts.UnitTestArtifactExplorationRunner.ProcessProject(IExplorationTarget target, CancellationToken token)

Sometimes I can work for an hour without it happening and sometimes it happen after five minuts. The only way to get away from it seems to be File -> Invalidates cache but it's a bit annoying to have to do it. 

Someone else that have seen the same issue and maybe found a way to fix it or a different workaround that don't require a restart? Can't find any other discussion about it so not sure if it's just a local thing but it happen in multiple different solution so it doesn't seems to be related to a single project/solution.