NVENC: Can't open 1440p encoder

Hello
I’m tying to open an NVENC encoder and every time I receive NVENCException: 8
Running on: Quadro M4000
Config:

encodeWidth:2560
encodeHeight:1440
darWidth:2560
darHeight:1440
maxEncodeWidth:2560
maxEncodeHeight:1440
frameRateNum:25
frameRateDen:1
enablePTD:1
profileGUID:NV_ENC_H264_PROFILE_MAIN_GUID
gopLength:60
frameIntervalP:1
encodeCodecConfig.h264Config.idrPeriod:60
encodeCodecConfig.h264Config.sliceMode:0
encodeCodecConfig.h264Config.sliceModeData:0
encodeCodecConfig.h264Config.level:40
encodeCodecConfig.h264Config.chromaFormatIDC:1
rcParams.rateControlMode:1
rcParams.averageBitRate:11059200
rcParams.maxBitRate:33177600

Limits, provided by nvEncGetEncodeCaps: NVENC LIMITS: MB/s 983040 w 4096 h 4096 MB/frame 65536
Can you please provide some comments on why this configuration is not a valid one?

Best regards, Daniil