Long HDMI cable run question

Hey all,
Recently purchased a Atem Mini Extreme ISO to use for a church production. Using 3xBirddog X1 cameras in 1080p59.94.

We are in a temporary space right now and I need to use long 50ft HDMI cables for the camera runs. Camera 1 and 2 have no issues, however on Camera 3 I am getting intermittent signal. Now as I understand it, Input 1 and 2 on the switcher are quite different than 3-8 and that is why I am having issues.

I've heard some people say using Fiber optic HDMI cables may help in this situation. Anyone have experience using a 50ft fiber optic hdmi cable on inputs 3-8?
My next question is that in the space we are eventually moving to, the cameras are going to be quite a distance from the switcher. My plan was to use OREI HDMI ethernet extenders for this...probably 300ft runs of ethernet. Am I going to be ok with doing this on with this switcher? Or am I going to run into a similar situation? My plan would be to use very short HDMI runs on both the transmitter and receiver side since they would be placed close enough to the switcher/camera.
Thanks

Have you A/B tested the 3rd cable by plugging it into port 1 or 2 yet and see if it has the same issues?
In my experience with long, monodirectional HDMI cables, they're hit and miss.

If I can, in those situations, I'll run an SDI cable instead, and convert it back to HDMI at the switcher with a converter (like the Micro Converter BiDirectional SDI/HDMI, probably 3G if you're just doing 1080p, these are good to have in the bag anyway) or I'll use a HDMI to Ethernet adapter, which can be a little more expensive but ethernet is cheaper than either SDI or HDMI in my experience and easier to terminate.

Thanks Fred, I've switched to HDMI-->Ethernet converters and all seems to be good so far.

Good to hear mate, it looks like the industry is going to broadcast over IP anyway so start building out your ethernet runs now