Requisition Header and Line comments not getting saved sometime in eProcurement Manage Requisition

We are at peopleTools version 8.57.10 and Application version 9.2 PUM33.

Customer is facing issue in eProcurement >Manage Requisition. After creating requisition from eProcurement, when they are trying to enter comment at Requisition Header or Line level comments, comments not getting saved sometime. It is not happening always for the same customer. i.e., the customer is able to enter comments and able to save comments. But sometime, don't know what they are doing/how they are doing transaction, the comments are not getting saved.

We are not able to identify the way they are transacting, and unable to replicate the issue. they are also unable to replicate the issue in non-prod.