previous employer tax deduction is not shown in the new form 16 part B due to this there is a difference in tax deducted & as per form 16 part B for those who have dual income. whereas the income is shown.
The Form 16 Part B is downloaded from Traces in pdf, then how changes will happen.
Traces will get the data from the Form 24Q returns.
If you want this to be corrected then you have to correct the Form 24Q and refile it.