opening preferences clips scrollback to 16384 lines
I have my scrollback set to 65535 lines. I was trying to find the key binding for scrollback search and opened the preferences window. I found the binding and tried the search and didn't find what I was looking for. It seems that opening the preferences window causes the scrollback to get clipped to 16834 lines. I verified this by saving the history to a file and using wc, which returned 16388 lines. I had added 4 lines to the scrollback prior to saving the history.
Using the xfce4-terminal-1.1.0-1.fc39.x86_64 in Fedora 39.