Frameless output: floating table column headers with postion: sticky don't work

Hello,

I have several tables where I've used CSS selectors to apply position: sticky to the table cells in the first row of that table. This is a a fairly standard method to create floating column header for long tables where context may be lost. This method works as expected in Responsive HTML 5 output.

However, position: sticky does not work as expected when used with the Frameless output type. I suspect this has something to do with the DIVs in the Frameless output, specifically .RH-LAYOUT-TOOLBAR-toolbar-box, which also has position: sticky.

Is there some known workaround to potentially allow floating table headers to work? I've already tried a few JS-based solutions (such as floatThead), but the Frameless output also interacts with those in odd ways.

Thank you in advance!