Please understand HR is not a disciplinary agency or superior to others.
Complaints about late coming, wastage of time is initially with HOD and not directly HR.
Office politics is at play here and mid of your HR boss is biased against you to some extent.
You being too friendly initially and now being distant has caused bad blood.
How is it that the HOD of the employees is not being objected by their HOD as he is primarily responsible for their output.
Ignore the attitude of these employees for the time being.
Sooner or later their time wasting will come to notice of other officials also.
Any action initiated by you in the circumstances will bounce on you as your boss is upset and the employees are not counselled by their own HOD.
14th August 2018 From India, Pune
As an adult , nobody likes to be told or behave even though he is at fault. However unpleasant, it is each HOD's foremost responsibility to enable team discipline and team spirit. Your role as HR is only that of catalyst .
For the time being forget what happened with the truant ladies and your boss and move forward doing your job with clarity and conviction about your role which is well- founded on HR beliefs and principles .
15th August 2018 From India, Mumbai
You seem to have been misguided by your HR head.
It is the problem of wasting time should have been reported to HR head by concerned department,if they could not handle the issue themselves.
For now , suggested course,if to try and forget the issue and lean from this episode
17th August 2018 From India, Delhi
3rd January 2019 From India, Pune