Latest NVIDIA DLSS DLL 2.3.4 files have been released, which is dated November 10th! Battlefield 2042 DLSS is dated 24/09/21 so nearly two months older.
Backup nvngx_dlss.dll and replace with the one included in this file
https://www.techpowerup.com/download/nvidia-dlss-dll/
You tried this yet?
Edit - I just tried it, made zero difference for me,