Sortable issue

I have this code, it pick the value of profit_or_lose from the database:

                Tables\Columns\TextColumn::make('profit_or_lose')
                    ->sortable()
                    ->label('P/L'),

                Tables\Columns\TextColumn::make('profit_or_lose')
                    ->sortable()
                    ->label('P/L'),

But it does not sort the right way? Does anyone know what this can be?