Entity Framework - DbUpdateConcurrencyException due to a trigger on the table

Microsoft.EntityFrameworkCore.DbUpdateConcurrencyException: Database operation expected to affect 1 row(s) but actually affected 0 row(s). Data may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=527962 for information on understanding and handling optimistic concurrency exceptions.

public async Task<Response<bool>> Handle(UpdateLastOperationCommand request, CancellationToken cancellationToken)
{
    var routeCard = await _myDbContext.RouteCards.FirstOrDefaultAsync(n => n.RouteNo == request.RouteNo);
    var routeOperations =
        await _myDbContext.RouteCardOps.Where(n => n.RouteNo == request.RouteNo).ToListAsync();
    var ordered = routeOperations.OrderBy(n => n.Seq);
    var lastOp = ordered.LastOrDefault();

    if (lastOp == null)
    {
        return new Response<bool>() { Succeeded = true, Data = false, Message = "No operation to update" };
    }

    routeCard.QtyFinished = lastOp.QtyComplete;
    if (routeCard.QtyFinished >= routeCard.BatchQty)
    {
        Log.Information($"RouteCard should be marked as complete");
        routeCard.RouteStatus = "CMP";
        routeCard.StatusDate = DateTime.Now;
        routeCard.CompletedDate = DateTime.Now;
        routeCard.SignOff = lastOp.SignOff;
        routeCard.SignOffOn = lastOp.SignOffOn;
    }

    await _myDbContext.SaveChangesAsync();
    Log.Information($"Successfully updated route card {request.RouteNo}");

    return new Response<bool>() { Succeeded = true, Data = true };
}