The voxl-portal does not handle well streaming large images (including in multi-view, where the images are actually appearing small). The voxl-portal back-end uses software JPEG encoding, so one of your streams (hires_large) is 4208x3120, which takes LOT of cpu processing to encode to jpeg.
You can see that the voxl-portal process uses 260% cpu (2.6 full cores), which is a lot.
There is no practical need for streaming small and large uncompressed images to voxl-portal, so you can just enable small video stream, which is much smaller.
Also, if you select an individual camera stream, you can enable advanced camera controls (click on the small check box in lower left) and then you can adjust the JPEG encode quality from default 70 to something much lower in order to use less cpu. This setting will be applied to all cameras and you can go back to multi view after that. Note that the jpeg encode quality only affects voxl-portal view, not h264/h265 encoding.
Please try.
Alex
