Kitty and Alacritty needs OpenGL3 to work and are only able to be executed with some custom environment flags in place at the moment (see [ARM Stable Update] 2020-10-27 - KDE Plasma, Firefox, Uboots and Kernels).
I gave Alacritty a try with these overrides and noticed that neovim behaves in a proper way with it. So the issue might be related to termite not reporting screen space on-time for neovim to catch up… doing a force screen refresh usually results in neovim catching up in termite though.