Hello   @Amit-M 

We made a guide to troubleshooting the unstable issue on the extender, please try some tips listed there.

Troubleshooting Range Extender Keeps Losing Connection

Confirm your extender is on the latest firmware 

May I know the model number & Led status on the extender when the problem occurs? If  possible, please help also attach some information requested there like model of router, frequency of the issue etc. those would be of great help to look into the case further or fix the problem.