Need to replicate only immidiate next row in excel if row contains specific string

Hello,

I have created automation for Jira work orders which fetch tickets from jira with user details using api and work on that and delivers ticket.
Automation first checks user id or email id in corp directory first and if user is valid then only proceed for next steps.
issue i am facing is -
consider 2 examples
1] user has provided all proper user id’s in ticket in users field-
kmathkar,ajosu,rkumar - all 3 are right and able to find in corp directory so proceeded successfully for this ticket.
2] user has provided lastname,first name for first user and for second user proper username
kumar,manoj,kmathkar - here automation will consider there are three saperate usernames and will serach in corp directory.
for kumar it will not able to get details as it is not username or may be (there are 10% chances there is username with kumar)
for manoj it will not able to it details or may be (there are 50% chances there is username with manoj)
and kmathkar is proper username so automatio will proceed with that.

so here issue is in case if it able to found details for manoj/kumar then it will be wrong and next process will executed for wrong users.

so tro avoid that i am thinking , for if last name is wrong then automation will write wrong user and immidiate next line also write as wrong user.so how can i achieve that? i need to write only immidiate line as same as for last name so it will not proceed for this 2.
here is the excel - after doing corp directory validation

once above file is done i need to moddify like below -my expected output will be -

how can i achieve this? or can you suggest different approch to handle this? any linq expression?

@Mathkar_kunal

How can you identify the line item uniquely? using Users column?

I will assume Users column for now, and follow below steps:

  1. Find index of current row => idx = Dt.Rows.IndexOf(CurrentRow)
  2. Update rows if wrong user: Assign1 dt.Rows(idx)(“Comments”)=“Wrong User”, Assign2 dt.Rows(idx+1)(“Comments”)=“Wrong User”

Hope this helps.