purch group automatically changed in work order

Hi All,

Good day!

I would like to request your assisntace on the below issue;

When creating a PM01 Work Order with a PM03 Control Key, user selects B99 for purchasing group after completing  external tab the purchasing group changed to V22 so the user has to change it again to B99 on the operations>external tab.

This issue occurs when the user is trying to create a work order with PM03 control key. We’ve checked the
configuration but there is no default purchasing group. Also, the user has no default parameters .

I would like to know what needs to be checked/maintained for the issue not to encounter again

Thanks,

Aisha