The File name column expands so the longest file name in the folder fits. With long file names the column can expand longer than the Thunar window is wide, effectively hiding other columns so you have to scroll the window to the right to be able to see the other columns and resize the name column. I have long file names in my home folder so every time I open Thunar the column is expanded and I have to resize it to be able to see and work with other columns. I would like to have fixed sizes of columns, never auto resizing. Detailed list view. The autoresize is in effect until you manually resize a column. From then on that column stays your desired size, other columns not touched still autoresizes.
There is already a solution in place for your problem: Please open settings-editor (from the application menu, or type "xfce4-settings-editor" in a console ) In the category "thunar" you now can find "last-details-view-fixed-columns". Check the checkbox, close the window and restart thunar. Did it work for you ?
Thanks. Installed xfce4-settings (on a Gnome3, ubuntu 17.10 system) That setting is missing, closest I find is "/last-details-view-column-widths" but I can't tick any of the Locked boxes, even when opening settings as su. I get "Gtk-Message: Failed to load module "overlay-scrollbar"" which seems to be the problem.
I have xfce4-settings v4.12.1-1 installed here, that's the one from my dist ( debian stretch ) do you have something older ? I dont know what is the purpose of "lock" .. .I did not use it. Dont use it as root, all these settings are user-specific! For me it did not even start as root.