To those of you that choose to upgrade the vtx in your hawk 5, like I did with the AKK infinite VTX/DVR (in this walkthrough here) I've updated my recommendation for the powersupply. Previsouly I relied on the flight controller's 5v BEC circuit that also powers the receiver and of course the board itself. I've now updated this recommendation to use the VBAT (or VCC) power supply instead assuming of course your VTX can take up to 24V as most modern full-sized VTXs can, including the AKK infinite I installed. This is because the BEC struggles at higher output making the video feed noisy. Over the longer term this is likely to irreversible damage the BEC rendering the flight controller pretty well useless but not before having random failures as a result of the compromised BEC. Picture below is using the power supply from the original VTX - the flight controller's 5V BEC:
So long as you have a VTX that can accept higher voltages, please use the VCC pad to provide power to your VTX alongside the ground pad next to it. This will bypass the flight controller BEC completely and leav you free to use any and all functions on the VTX. This can be clearly seen circled in the image below and on the quad itself
This is a simple change but will clean up your video and place less stress on your BEC. In hindsight this is maybe why some people are struggling with the stock VTX - it may not be the vtx at all, rather that power that is supplying it that is the issue.
My original Hawk 5 VTX install/walkthrough guide is here and other bang for buck modifications I made to the hawk 5 are here.