Dashboard missing on frontpage

i’m a bit dumb but earlier i had this plugin installed:

https://www.ads-software.com/plugins/gtmetrix-for-wordpress/

and right after i installed it, my dashboard gone missing on the frontpage but it shows normally in my posts.

how could that happen? and how to fix it? i tried clearing up my database and restore it, remove and reupload my wordpress files.

but the problem still showed up. ??