GPU load drops to 0% when playing multicam sequence

Hi dear,

my multicam sequence (3x sony FS7+FS5+x70) not plays continuous when I activate multicam monitor. I have Nvidia Quadro 5100M in notebook HP and Nvidia GTX980 in desktop computer (win10, CC2018). Im traying booth. In first 5 seccond GPU load drops do 0%. CPU is 100%.

In project setting I can activate CUDA playback. In nvidia control panel i set as preferred card Nvidia.

Please, can you help me?