How do I get rid of the strange box near my cursor

Hi there

Hope you are doing well and sorry for the trouble. As described a gray box appears to the bottom left of the cursor.

Are you referring to the grey box near the mouse cursor/pointer? If yes, this appears when you select the select tool form Adobe Acrobat/Reader. It is a design behavior and there isn't much that can be done in this situation.

You may share your feedback to the engineering team using the link https://acrobat.uservoice.com/

You may also check the similar discussion https://community.adobe.com/t5/acrobat/what-is-this-strange-box-near-my-mouse-cursor-how-to-remove-it/td-p/10633133

Regards

Amal