tile shows "_" (underscore) instead of value "0"

[tectumopticum]

Describe the bug

When a host-variable is set to "0" (string- or number-variable with value zero) the tile only displays an underscore-character.

To Reproduce

1. create a host-template with a custom-var
2. create a host-object, import the template, set the custom-var to "0", deploy
3. create a new Cube, "Add a dimension" and choose the custom-var

Expected behavior

The value "0" should be displayed as correct value and not be replaced by underscore "_" or other characters

Screenshots

Your Environment

• Icinga Web 2 version and modules (System - About): 2.12.5
• Web browser used: Firefox, Edge
• Icinga 2 version used (icinga2 --version): 2.15.1
• PHP version used (php --version): 8.3.23
• Server operating system and version: SLES 15 SP7