Force composition pipeline required - otherwise flickering

running fedora 33 with akmod-nvidia i have flickering on my primary display.
the left display runs with dvi on 144hz without problems, the right one runs on DP with 165hz but flickers when not using force composition pipeline.
i guess thats a bug because i would expect that this runs fine without composition pipeline

see also https://bugzilla.rpmfusion.org/show_bug.cgi?id=5813

display: :0.0 screen: 0
API version: 1
Information string: NVIDIA VDPAU Driver Shared Library 455.28 Wed Sep 30 00:56:49 UTC 2020

Video surface:

name width height types

420 8192 8192 NV12 YV12
422 8192 8192 UYVY YUYV
444 8192 8192 NV24 YV24

Decoder capabilities:

name level macbs width height

MPEG1 0 65536 4096 4096
MPEG2_SIMPLE 3 65536 4096 4096
MPEG2_MAIN 3 65536 4096 4096
H264_BASELINE 51 65536 4096 4096
H264_MAIN 51 65536 4096 4096
H264_HIGH 51 65536 4096 4096
VC1_SIMPLE 1 8190 2048 2048
VC1_MAIN 2 8190 2048 2048
VC1_ADVANCED 4 8190 2048 2048
MPEG4_PART2_SP 3 8192 2048 2048
MPEG4_PART2_ASP 5 8192 2048 2048
DIVX4_QMOBILE 0 8192 2048 2048
DIVX4_MOBILE 0 8192 2048 2048
DIVX4_HOME_THEATER 0 8192 2048 2048
DIVX4_HD_1080P 0 8192 2048 2048
DIVX5_QMOBILE 0 8192 2048 2048
DIVX5_MOBILE 0 8192 2048 2048
DIVX5_HOME_THEATER 0 8192 2048 2048
DIVX5_HD_1080P 0 8192 2048 2048
H264_CONSTRAINED_BASELINE 51 65536 4096 4096
H264_EXTENDED 51 65536 4096 4096
H264_PROGRESSIVE_HIGH 51 65536 4096 4096
H264_CONSTRAINED_HIGH 51 65536 4096 4096
H264_HIGH_444_PREDICTIVE 51 65536 4096 4096
VP9_PROFILE_0 1 262144 8192 8192
VP9_PROFILE_1 — not supported —
VP9_PROFILE_2 1 262144 8192 8192
VP9_PROFILE_3 — not supported —
HEVC_MAIN 153 262144 8192 8192
HEVC_MAIN_10 153 262144 8192 8192
HEVC_MAIN_STILL — not supported —
HEVC_MAIN_12 153 262144 8192 8192
HEVC_MAIN_444 — not supported —

Output surface:

name width height nat types

B8G8R8A8 32768 32768 y Y8U8V8A8 V8U8Y8A8 A4I4 I4A4 A8I8 I8A8
R10G10B10A2 32768 32768 y Y8U8V8A8 V8U8Y8A8 A4I4 I4A4 A8I8 I8A8

Bitmap surface:

name width height

B8G8R8A8 32768 32768
R8G8B8A8 32768 32768
R10G10B10A2 32768 32768
B10G10R10A2 32768 32768
A8 32768 32768

Video mixer:

feature name sup

DEINTERLACE_TEMPORAL y
DEINTERLACE_TEMPORAL_SPATIAL y
INVERSE_TELECINE y
NOISE_REDUCTION y
SHARPNESS y
LUMA_KEY y
HIGH QUALITY SCALING - L1 y
HIGH QUALITY SCALING - L2 -
HIGH QUALITY SCALING - L3 -
HIGH QUALITY SCALING - L4 -
HIGH QUALITY SCALING - L5 -
HIGH QUALITY SCALING - L6 -
HIGH QUALITY SCALING - L7 -
HIGH QUALITY SCALING - L8 -
HIGH QUALITY SCALING - L9 -

parameter name sup min max

VIDEO_SURFACE_WIDTH y 1 8192
VIDEO_SURFACE_HEIGHT y 1 8192
CHROMA_TYPE y
LAYERS y 0 4

attribute name sup min max

BACKGROUND_COLOR y
CSC_MATRIX y
NOISE_REDUCTION_LEVEL y 0.00 1.00
SHARPNESS_LEVEL y -1.00 1.00
LUMA_KEY_MIN_LUMA y
LUMA_KEY_MAX_LUMA y