Found updated NFB (New Feature Branch) of #nvidia #GPU driver sets 575.64.03.
Filed PR for #FreeBSD #ports as Bug 287984
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=287984
and opened corresponding review D51144
https://reviews.freebsd.org/D51144
Patch there is for "-devel" variant of ports like x11/nvidia-driver-devel.
Runnign on stable/14, amd64 until last night without new issue for me.
But as my GPU on hand is old (Quadro P1000 notebook), cannot confirm that the new version solves any of known problems on GPUs with GSP in them by myself.