Cfwindow not displaying scrollbars on IE for CF 2019 version 5 update

Use DevTools (F12) when loading the CFWINDOW to see if there are any console error messages that appear.

HTH,

^ _ ^

I recently had problems with cfwindow because CF 2018 update 2 (which would be cumulatively included in update 5) updates the javascript library behind cfwindow. It's called ExtJs and it was updated from version 4.x to 6.x.  I don't know what all changed, but I had to replace the cf_scripts\scripts\ajax\ext and cf_scripts\scripts\ajax\resources\ext folders with copies from a previous installation to get the functionality back to what it was before update 2. (My issue had to do with centering the window.)

I don't know if that will fix your issue, but it might be something to look at, especially if your scroll bars worked in an older version.