Welcome to PF1 - personally I'd use the shortest distance Telephone cable between the router and POE and then use the Cat6 from the router to PC, Mind you cat6 wont be any faster than cat5 if the hardware cant take it, the distance cat5 starts to get "picky" is approx 100M. Long lines from the POE to router have been known to cause problems.
I have cat5 going from my router out to the workshop which is about 40mtrs away as the crow flies, going round corners/walls etc easily to 50 + mtrs and the PC's out there are no slower than this PC which is about 1 Mtr from the router.


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