plugin cause lagg

hello i’am using this plugin from long time its work great, but i made few changes in theme such as add padding, change little design and suddenly my site start lagging, when i disable this plugin everything work fine please fix that i want use this plugin again my theme is basic by themify. i think padding and small areas where ads not fit properly cause problems.

https://ww.wp.xz.cn/plugins/ad-inserter/