AMP is adding characters on the url

Hi there,

we having AMP running only on posts.

Hoster: WPengine, PHP7, Avada Theme

Since the last Update AMP is adding something on the url:

https://www.mywebsite.xxx/post/amp/?usqp=mq331AQCCAE

Also i can reach the post under

https://www.mywebsite.xxx/post/amp/

I resaved the permalinks already but still this problem.

Please help! Cheers

Nancy