For the benefit of others who may run into a similar problem. Everything starts with knowing, understanding, and following the local codes in your area.
Trench: The line must be trenched to whatever depth called out by NEC / CEC. Whether that be 12-18” vs 24-32”. If code indicates some kind of aggregate is to be used - do it. This serves to protect the cable from frost, roots, rodents, and helps in long term drainage.
If the same is called out to be placed on top - do it.
Flag tape should be inserted if required but should be done anyways so you or others can find the wire!
Conduit: This should be used where rodents / tree roots are pervasive. Bigger is always better which allows easier pulls and extra cable. A pull string should always be left for future pulls. It goes without saying gluing all the pipes correctly is paramount as this slows down the process of water penetration / build up.
Safety: Generally speaking low voltage and high voltage cabling can not share the same trench / conduit. Unless the material & medium is rated as such and follows all the relevant codes.
Grounding: Anything that comes in / out of the house as it relates to power. Must be connected / bonded to the single point Earth ground of the buildings electrical service. Any isolated system must be properly grounded if deployed as such. Meaning a ground rod must be installed and the correct (AWG) gauge wire used for the distance and fault current expected to be seen / carried.
The appropriate stainless steel hardware, star washer, ring connector, and rust inhibitor such as dielectric grease, must be used.
Shielding: Anytime you break 25 feet in electrical wire as it relates to Ethernet cable and where the environment is subjected or prone to RFI, EMI, EMF, Lightning. Shielded cable should be used and properly grounded to the network infrastructure that is bonded at every point from rack, switch, patch panel, to ground bar.
Cable: The cable should be outdoor rated for the environment and intended purpose. Whether that be exposed (UV) rated, direct burial , shielded, gel filled. It should be laid flat with no kinks or sharp bends.
Testing: Basic to advanced tests should be completed before the cable is buried. This spans from a simple correct wiring, continuity, voltage drop, and resistance. A load test as simple as connecting the camera to the system is practical. But testing for latency using ping and throughput must be validated also.
A managed switch is extremely helpful to help validate the power consumption, data I/O, and packet errors.
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Having stated all the above before you rip out any cable out. Validate the entire network infrastructure is sound. Could be a bad camera, switch, port, router, injector, splitter.
Remove one thing to test & validate. Move down the line of process of elimination. If all electronics have passed at least you know the hard work was worth the effort to pull 200’ of buried cable!

Test - Validate - Don’t guess . . .