JavaScript exception when previewing & editing templates

> I apologise if this is a duplicate post: I searched the forum & haven’t found anything, but I may be using the wrong search terms.
> If I edit the Card Template, navigate to Front, Back, or Styling, then tap Preview, things work as expected. If I remain within Card Template, navigate back to one of those first three categories, then return to Preview again, I get an error: **Error:** A JavaScript exception occurred. Thus, if I’m editing Styling, for example, & want to check back & forth on the effects of my CSS, I need to exit Card Template & re-enter after each round of edits. This error has been consistent since I began using AnkiMobile a year ago.
> I am using AnkiMobile 25.02.02 on an iPhone 15 Pro Max running iOS 18.4.1.

Originally reported on https://forums.ankiweb.net/t/javascript-exception-on-second-card-template-preview/60753