最近Centos 7に切り替えましたが、HDMI経由でセカンダリモニタを接続すると奇妙な現象が発生します。 GNOMEは2台目のモニターが接続されていることを認識できますが、マウスを2台目のモニターに移動するとマウスのみが表示されます。残りは黒です。メイン画面から補助画面にウィンドウをドラッグすると、闇に囲まれて拳を握った姿だけが見えます。
私はCentos Linuxバージョン7.4.1708（コア）とGNOME 3.22.3を実行しています。
の出力はxrandr -q、
Screen 0: minimum 320 x 200, current 3840 x 1080, maximum 8192 x 8192
eDP-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
1920x1080 60.02*+ 48.03
1400x1050 59.98
1280x1024 60.02
1280x960 60.00
1024x768 60.04 60.00
960x720 60.00
928x696 60.05
896x672 60.01
800x600 60.00 60.32 56.25
700x525 59.98
640x512 60.02
640x480 60.00 59.94
512x384 60.00
400x300 60.32 56.34
320x240 60.05
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1-1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 476mm x 268mm
1920x1080 60.00*+ 50.00 50.00 59.94
1680x1050 59.88
1400x1050 59.98
1600x900 60.00
1280x1024 60.02
1440x900 59.90
1280x960 60.00
1280x800 59.91
1280x720 60.00 50.00 59.94
1024x768 60.04 70.07 60.00
960x720 60.00
928x696 60.05
896x672 60.01
800x600 70.00 65.00 60.00 60.32 56.25
720x576 50.00
700x525 59.98
720x480 60.00 59.94
640x512 60.02
640x480 60.00 60.00 59.94
720x400 70.08
512x384 70.07 60.00
400x300 60.32 56.34
320x240 60.05
1400x1050 (0x4a) 122.000MHz +HSync +VSync
h: width 1400 start 1488 end 1640 total 1880 skew 0 clock 64.89KHz
v: height 1050 start 1052 end 1064 total 1082 clock 59.98Hz
1280x1024 (0x4c) 108.000MHz +HSync +VSync
h: width 1280 start 1328 end 1440 total 1688 skew 0 clock 63.98KHz
v: height 1024 start 1025 end 1028 total 1066 clock 60.02Hz
1280x960 (0x4e) 108.000MHz +HSync +VSync
h: width 1280 start 1376 end 1488 total 1800 skew 0 clock 60.00KHz
v: height 960 start 961 end 964 total 1000 clock 60.00Hz
1024x768 (0x53) 133.475MHz -HSync +VSync DoubleScan
h: width 1024 start 1100 end 1212 total 1400 skew 0 clock 95.34KHz
v: height 768 start 768 end 770 total 794 clock 60.04Hz
1024x768 (0x55) 65.000MHz -HSync -VSync
h: width 1024 start 1048 end 1184 total 1344 skew 0 clock 48.36KHz
v: height 768 start 771 end 777 total 806 clock 60.00Hz
960x720 (0x56) 117.000MHz -HSync +VSync DoubleScan
h: width 960 start 1024 end 1128 total 1300 skew 0 clock 90.00KHz
v: height 720 start 720 end 722 total 750 clock 60.00Hz
928x696 (0x57) 109.150MHz -HSync +VSync DoubleScan
h: width 928 start 976 end 1088 total 1264 skew 0 clock 86.35KHz
v: height 696 start 696 end 698 total 719 clock 60.05Hz
896x672 (0x58) 102.400MHz -HSync +VSync DoubleScan
h: width 896 start 960 end 1060 total 1224 skew 0 clock 83.66KHz
v: height 672 start 672 end 674 total 697 clock 60.01Hz
800x600 (0x5b) 81.000MHz +HSync +VSync DoubleScan
h: width 800 start 832 end 928 total 1080 skew 0 clock 75.00KHz
v: height 600 start 600 end 602 total 625 clock 60.00Hz
800x600 (0x5c) 40.000MHz +HSync +VSync
h: width 800 start 840 end 968 total 1056 skew 0 clock 37.88KHz
v: height 600 start 601 end 605 total 628 clock 60.32Hz
800x600 (0x5d) 36.000MHz +HSync +VSync
h: width 800 start 824 end 896 total 1024 skew 0 clock 35.16KHz
v: height 600 start 601 end 603 total 625 clock 56.25Hz
700x525 (0x5f) 61.000MHz +HSync +VSync DoubleScan
h: width 700 start 744 end 820 total 940 skew 0 clock 64.89KHz
v: height 525 start 526 end 532 total 541 clock 59.98Hz
640x512 (0x62) 54.000MHz +HSync +VSync DoubleScan
h: width 640 start 664 end 720 total 844 skew 0 clock 63.98KHz
v: height 512 start 512 end 514 total 533 clock 60.02Hz
640x480 (0x63) 54.000MHz +HSync +VSync DoubleScan
h: width 640 start 688 end 744 total 900 skew 0 clock 60.00KHz
v: height 480 start 480 end 482 total 500 clock 60.00Hz
640x480 (0x65) 25.175MHz -HSync -VSync
h: width 640 start 656 end 752 total 800 skew 0 clock 31.47KHz
v: height 480 start 490 end 492 total 525 clock 59.94Hz
512x384 (0x68) 32.500MHz -HSync -VSync DoubleScan
h: width 512 start 524 end 592 total 672 skew 0 clock 48.36KHz
v: height 384 start 385 end 388 total 403 clock 60.00Hz
400x300 (0x69) 20.000MHz +HSync +VSync DoubleScan
h: width 400 start 420 end 484 total 528 skew 0 clock 37.88KHz
v: height 300 start 300 end 302 total 314 clock 60.32Hz
400x300 (0x6a) 18.000MHz +HSync +VSync DoubleScan
h: width 400 start 412 end 448 total 512 skew 0 clock 35.16KHz
v: height 300 start 300 end 301 total 312 clock 56.34Hz
320x240 (0x6b) 12.587MHz -HSync -VSync DoubleScan
h: width 320 start 328 end 376 total 400 skew 0 clock 31.47KHz
v: height 240 start 245 end 246 total 262 clock 60.05Hz