Strange character since last update (>4;2m) in vim

Question

I've recently update vim on ubuntu, and since then, a strange character keep appearing at random time at my cursor place. It seems to appear when I do nothing for some seconds. The character is >4;2m and I can't understand the logic of its appearance. Has anyone the same problem ? Switching buffer and coming back to the initial one clean the character.

vim --version :

VIM - Vi IMproved 8.2 (2019 Dec 12, compilé May 21 2020 15:41:59)
Rustines incluses : 1-803
Modifié par [email protected]
Compilé par [email protected]
Énorme version avec interface graphique GTK3.
  Fonctionnalités incluses (+) ou non (-) :
+acl               -farsi             +mouse_sgr         +tag_binary
+arabic            +file_in_path      -mouse_sysmouse    -tag_old_static
+autocmd           +find_in_path      +mouse_urxvt       -tag_any_white
+autochdir         +float             +mouse_xterm       +tcl
-autoservername    +folding           +multi_byte        +termguicolors
+balloon_eval      -footer            +multi_lang        +terminal
+balloon_eval_term +fork()            -mzscheme          +terminfo
+browse            +gettext           +netbeans_intg     +termresponse
++builtin_terms    -hangul_input      +num64             +textobjects
+byte_offset       +iconv             +packages          +textprop
+channel           +insert_expand     +path_extra        +timers
+cindent           +ipv6              +perl              +title
+clientserver      +job               +persistent_undo   +toolbar
+clipboard         +jumplist          +popupwin          +user_commands
+cmdline_compl     +keymap            +postscript        +vartabs
+cmdline_hist      +lambda            +printer           +vertsplit
+cmdline_info      +langmap           +profile           +virtualedit
+comments          +libcall           -python            +visual
+conceal           +linebreak         +python3           +visualextra
+cryptv            +lispindent        +quickfix          +viminfo
+cscope            +listcmds          +reltime           +vreplace
+cursorbind        +localmap          +rightleft         +wildignore
+cursorshape       +lua               +ruby              +wildmenu
+dialog_con_gui    +menu              +scrollbind        +windows
+diff              +mksession         +signs             +writebackup
+digraphs          +modify_fname      +smartindent       +X11
+dnd               +mouse             +sound             -xfontset
-ebcdic            +mouseshape        +spell             +xim
+emacs_tags        +mouse_dec         +startuptime       +xpm
+eval              +mouse_gpm         +statusline        +xsmp_interact
+ex_extra          -mouse_jsbterm     -sun_workshop      +xterm_clipboard
+extra_search      +mouse_netterm     +syntax            -xterm_save
         fichier vimrc système : "$VIM/vimrc"
     fichier vimrc utilisateur : "$HOME/.vimrc"
 2me fichier vimrc utilisateur : "~/.vim/vimrc"
      fichier exrc utilisateur : "$HOME/.exrc"
        fichier gvimrc système : "$VIM/gvimrc"
    fichier gvimrc utilisateur : "$HOME/.gvimrc"
2me fichier gvimrc utilisateur : "~/.vim/gvimrc"
 fichier de valeurs par défaut : "$VIMRUNTIME/defaults.vim"
          fichier menu système : "$VIMRUNTIME/menu.vim"
               $VIM par défaut : "/usr/share/vim"
Compilation : gcc -c -I. -Iproto -DHAVE_CONFIG_H -DFEAT_GUI_GTK  -pthread -I/usr/include/gtk-3.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/at-spi-2.0 -I/usr/include/dbus-1.0 -I/usr/lib/x86_64-linux-gnu/dbus-1.0/include -I/usr/include/gtk-3.0 -I/usr/include/gio-unix-2.0/ -I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/pango-1.0 -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libpng16 -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -Wdate-time  -g -O2 -fdebug-prefix-map=/build/vim-azHx0p/vim-8.2.0803=. -fstack-protector-strong -Wformat -Werror=format-security -D_REENTRANT -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1       
Édition de liens : gcc   -L. -Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,-z,now -fstack-protector -rdynamic -Wl,-export-dynamic -Wl,-E  -Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,-z,now -Wl,--as-needed -o vim   -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -latk-1.0 -lcairo-gobject -lcairo -lgdk_pixbuf-2.0 -lgio-2.0 -lgobject-2.0 -lglib-2.0 -lSM -lICE -lXpm -lXt -lX11 -lXdmcp -lSM -lICE  -lm -ltinfo  -lselinux  -lcanberra -lacl -lattr -lgpm -ldl  -L/usr/lib -llua5.2 -Wl,-E  -fstack-protector-strong -L/usr/local/lib  -L/usr/lib/x86_64-linux-gnu/perl/5.26/CORE -lperl -ldl -lm -lpthread -lcrypt  -L/usr/lib/python3.6/config-3.6m-x86_64-linux-gnu -lpython3.6m -lpthread -ldl -lutil -lm -L/usr/lib/x86_64-linux-gnu -ltcl8.6 -ldl -lz -lpthread -lm -lruby-2.5 -lpthread -lgmp -ldl -lcrypt -lm     

Answer 1

It was a problem of modifyOtherKeys. After looking at the doc, putting

let &t_TI = ""
let &t_TE = ""

in my vimrc solved the problem.