That's caused by the following commit removing a deprecated API from libvte: https://gitlab.gnome.org/GNOME/vte/-/commit/a0bb8222f3a0a29e4f22817bf3d7053d185b7afb
Upstream LXTerminal has fixed this issue in the following commit: https://github.com/lxde/lxterminal/commit/b1e3db193651b33db1e112a71ccc1e9868f37093
