It is possible to scroll background, when mouse pointer is placed on the top of the expanded hint box. Issue can be reproduced in different forms, for example: item form, media,

Steps to reproduce:
Example from a trigger form:

1. Open: Data collection -> Hosts -> Any existing host -> Trigger -> Create trigger
2. Click on the hintbox next to Menu entry name field
3. Place the mouse pointer on the expanded hintbox
4. Scroll the page

Result: background is scrolling

See video:

Example from a test item form:

1. Start server
2. Open: Data collection-> Hosts -> Any existing host -> Create item
3. Add some parameters, so it would be possible to test item / preprocessing, for example:

   Item key: test
   Type: Zabbix trapper
   Type of information: Text
   

1. Click preprocessing
2. Add step -> Discard unchanged (or any other for hint-box with result to appear)
3. Click Test for preprocessing
4. Add some text value, for example:

   Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et
   

1. Click test
2. Click on the result
3. Place the mouse pointer on the expanded hintbox
4. Scroll the page

Result: The background (item list) is scrolling.

See video:

Expected:
Background should not scroll