To activate my wifi i need to connect my ethernet cable latop

Hello,

I have a very different issue , plz suggest

I use interent thro my wifi router for past 6 months with my service provider .

recently wifi was not working . i.e it will get connected but pages wont display.

if i connect my lap wit ethernet cable , internet will work ..

And most unique thing is , to activate my wifi i need to connect my ethernet cable to my lap once and have to use internet for a while and then have to remove the ethernet cable and insert it back to modem . only by doin this i m able to use my internet thro my wifi modem

plz suggest . i use TP-Link and my service providers are not giving me any solutions