HDMI Extender over Ethernet recommendations

It's blowing your budget, but you can also look at the Ruipro fiber HDMI cables.  A 12 meter (39.37 feet) is $149.

https://www.amazon.com/RUIPRO-4K60HZ-HDMI2-0b-Supports-HDCP2-2/dp/B0759CXK4H?th=1

Not sure how they compare to ethernet extenders, but the Ruipro has gotten very good feedback and excellent 4K HDR support.

Re-reading some of your posts, I have some additional comments. 

I have found that Amazon's newer O/S for Fire TV may not necessarily work with older processors/receivers.  I had some problems getting my older FireTV unit to work through my Krell S1200U-3D (which is an HDMI 1.4a hardware).  You may want to try another type of streamer such as Roku, or invest in a better Zappiti or Zidoo streamer.

The new Yamaha receiver may be trying to do a 4K HDMI check.  That Beldon Series 1 cable is really not that great of a cable.  True, it is 23.5 awg for conductors and 24awg for control wires, but the copper is pretty poor quality (not even OFC), and the control wires use PVC insulation which really absorbs electrical energy.  It is likely that the Yamaha's HDMI signals are just not getting to the projector properly.