Hi Kuntal,
The resource units in percentage will be updated in the following scenarios,
1. When we edit the task resource unit manually using edit dialog.
2. Then while keeping the task type as fixed work or fixed duration and changing the duration will update the resource units.
We can restrict the units change by the following ways.
1. Keep the task type as fixed unit, then units will not change in any case so resource percentage will never show in grid part.
2. By default, the work, task Type and effort driven fields in Gantt was in hidden mode. We can avoid making these columns visible in the load event to prevent the unit change action.
Please try these ways and let us know if you need further assistance on this.
Regards,
Mahalakshmi K.