MSP430AFE253: performance variation in the low power mode.

Tool/software:

Dear Tech team,

We are using above part for the loop powered process indicator in the 4-20 mA loop. Its a indicator using low power 7 segment displays.

we have manufactured total 100 Qty cards & 40 pieces are found working OK but in other 60 cards are having issues.

There is a flickering of display during operation in balance 60 units & we have to replace the microcontroller multiple times to get stable display results, creating losses in inventory. 

Please suggest how to solve the problem as we are not able to proceed for the production.