Fluid Open Enrollment: Are alerts allowed in a fluid HBA text catalog id?

In Classic Open Enrollment we have some text that opens as an alert or a 'pop-up' message in the HEB/OPTN_HDR3 text catalog. When we try adding the same text into one of the fluid text catalog ids (HBA/PLAN/ENR_BEN_PLAN), it no longer works. Are alerts not allowed in the fluid HBA text catalog?

<SCRIPT type="text/javascript">

 var alert2l = sessionStorage.getItem('alert2l') || '';

  if (alert2l != 'yes') {

 alert("Evidence of insurability is required if you are electing coverage for the first time, increasing coverage by more than one level or requesting coverage of $50,000.");