[Response Rate Stuck at 91%]

About 15 days ago my resonse rate was drop down to less than 90% but after a few days it  become 91% and still it is there.

I response to my clients instantly. But response rate is not increasing yet.

My gig was demoted due to this drop down.

Please let me know what is the issue for it and how I CAN solve it?

Thank you so much 

[After Demoting my Gig my rank gig also drop]

Now my rating is above 90% 

and I am also stay active 

[After Demoting my Gig my rank gig also drop]

I was ranking on some specific keywords. I was on first page on 2 keywords. Due to some reasons I can't reply to my clients for 3 days and my gig was demote due to fell down in response rate less than 90%. So I wanna ask

My rank is fell down due to demote of my gig?

Kindly guide me