I have an nVidia graphics card and I installed the nVidia drivers through the Majaro hardware manager. In the most recent big Manjaro update it installed version 465 of the nVidia drivers. Previous to that the system had been using the 460 drivers. After the update I noticed OBS with nvenc was no longer working. When trying to record using OBS with the nvenc encoder it would complain about the encoder not being initialized properly. This occurred with both versions 26 and 27 of OBS.
I suspected it might have something to do with the new nVidia driver. If there’s a way to select which specific nVidia driver version you want to use with the Manjaro hardware settings tool I don’t know what it is so I removed the nvidia-driver package through the hardware settings manager then manually downloaded and installed the 460 driver from the nVidia website and now OBS works again.
So if anyone else is experiencing a similar issue it looks like the solution is to use the 460 driver.