Created attachment 8285 Video showing the two bugs The attached video has been made in a new terminal tab. As shown in the video, only one occurrence is found per line. This is not practical, especially when you have a terminal in fullscreen with two occurrences of the substring you're looking for at the beginning and at the end of the same line. The second problem is a bit trickier: when searching for a substring using "Previous", occurences are found only on the first and last "pseudo-lines" forming one long wrapped line. Searching with "Previous" works correctly when the terminal contains no wrapped lines. All of this happens both with and without wrap around. Thank you very much for your work and for your attention.
The first problem also occurs of course with non-wrapped lines.
Those are valid issues but they all belong to vte which is a terminal widget that xfce4-terminal (as well as some other terminal apps) is using. The one per line occurrence issue is a well-known one and has been reported as https://bugzilla.gnome.org/show_bug.cgi?id=694128 and a few other vte bugs. I wasn't able to find a bug report on the other issue so you might want to report it against vte here: https://gitlab.gnome.org/GNOME/vte
*** Bug 15728 has been marked as a duplicate of this bug. ***