When I placed the tooltip control inside a Modal section, making the modal section visible didnot make the tooltip control visible. I had to explicity add the code for making the Tooltip control also visible
SPARK Support
Tooltips do not display by default unless the “Show Tooltip” configuration option is selected in PD. If it is not, the setTooltipVisible() method needs to be used at runtime to show the tooltip.
Tooltip Article: https://salientprocess.zendesk.com/hc/en-us/articles/206416327-Tooltip