Hey there Ann98,
Not sure how that happened, would love to see some logs of that, information on time to first byte for your site:
https://www.webpagetest.org/
I’m thinking you were getting the increase whilst connecting to the Yahoo’s Smush service (waiting for a response) which is no longer online. Sadly Yahoo discontinued their service without prior notice.
We’ve just released an all new API of our own, this is much quicker than our previous one. If you could please give it another shot, you shouldn’t have an issue.
If you do have any problems, please open a support ticket and we’ll gladly help you with that:
https://www.ads-software.com/support/plugin/wp-smushit
Looking forward to getting this turned around for you.
Take care.