LINQ expression could not be translated after converting object

public static BugDTO ConvertToDTO(Bug bug) => new BugDTO
{
    Id = bug.Id,
    Description = bug.Description,
    IsFixed = bug.IsFixed
};

// GET: api/Bugs
//    api/Bugs?isFixed={true|false}
[HttpGet]
public async Task<ActionResult<IEnumerable<Bug /* BugDTO */>>> GetBugs([FromQuery] bool? isFixed)
{
    // var allBugDTO = _context.Bugs.Select(bug => ConvertToDTO(bug));
    var allBugDTO = _context.Bugs.Select(bug => bug);

    if (isFixed == null)
    {
        var allBugDTOList = await allBugDTO.ToListAsync();
        return allBugDTOList;
    }

    var filteredBugDTOList = await allBugDTO.Where(bug => bug.IsFixed == isFixed!).ToListAsync();
    return filteredBugDTOList;
}