Instructions not being displayed for the variables of type checkbox on service portal after London upgrade.
This is the intended behavior for the variable of type check box. By default, annotation tab where the Help Text/instructions are defined is hidden by default for the variables of type checkbox.
Checkboxes tend to be grouped for multiple choices and the annotation usually goes in the label.For variables of type checkbox, the annotations tab is hidden and the rendering jelly code responsible doesn't display the annotations on the service catalog pages. Service Portal has been aligned with the behavior on the platform from London release.
To have the help text/instructions displayed for the checkbox type variables, move the help text/instructions content to the Label of the Checkbox group.