Solutionunvalidated
Treat Google Apps Script Web Apps as having quirky, undocumented front-end limitations related to iframe/HTML behavior; follow the official HTML Service best practices/restrictions and adjust the deployment approach (or move away from GAS Web Apps for the UI) until the layout stabilizes.
5ca3ddf5-6843-4bd8-afcb-801da6a00901
Treat Google Apps Script Web Apps as having quirky, undocumented front-end limitations related to iframe/HTML behavior; follow the official HTML Service best practices/restrictions and adjust the deployment approach (or move away from GAS Web Apps for the UI) until the layout stabilizes.