One cause may be that the PC’s current supply is insufficient.
(Since it is not noise, repeater cables etc. cannot be used to deal with it.)
In particular, notebook PCs may have a low total amount of power supply or may be in power saving mode by default.
In this case, an easy solution is to use a self-powered HUB (HUB with an AC adapter).
The power supplied to the camera and active cable will now be supplied from the HUB, not the PC.
There are also self-powered HUBs with an ammeter as shown below.
