I can change the width of folder pane in the main folder tab, but not in subsequent folder tabs

I *can* resize the folder pane in the first/main folder tab, but, I *can not* resize the folder pane in subsequent folder tabs I create using "open in new tab". 

When I open a  folder in a new tab, the folder pane is the same width as the parent tab, but, I can't adjust it.

Hello, I *can* resize the folder pane in the first/main folder tab, but, I *can not* resize the folder pane in subsequent folder tabs I create using "open in new tab". This occurs using any layout (Classic, wide, vertical view). In the first tab I get the double-headed arrow to resize the folder pane, but in subsequent folder tabs I don't get it. When I open a folder in a new tab, the folder pane is the same width as the parent tab, but, I can't adjust it. I'm using Thunderbird 152.0.1, but, this has been going on for a long time from what I can remember. I've tried a number of suggested things to fix this: - Deleted xulstore.json - Cleared Startup Cache. - restarted in Troubleshoot mode (and I get the same issue there). - Switched layout views - Toggled folder modes - Adjusted interface density. - Toggled hardware acceleration. - Deleted the UI Cache Folder (shader-cache) Nothing worked. Please help me with this! Thank you, Jim