DC 12V 1A for 1-2 and 3-6 UTP twisted pair. Terminal - UPVEL switch. Who can tell me the physics of the process?

Question

Electronics

Home Internet. There is a 4-pair cable from the access switchboard, on the floor it splits into 2-pair and goes to my apartment. The length to the driveway is somewhere around 80m (if the fluke is not lying).
In normal mode (in summer), the resistance of pairs 1-2 and 3-6 is about 15-18 ohms. The rest of the time - about 20-22 ohms.
When the Internet disappears, then: inter-pair can reach 30-60 ohms. At what it is always skewed - either between 1-2 or between 3-6. Rarely, but it happens - that both pairs give such resistance.
Found a solution: a PSU from a 12V-1A scanner. I connect to 1-2 or 3-6 (depending on where the skew is). For 3-5 seconds. Either 1 time or 2-3 times. The resistance of the pairs equalizes. The Internet appears.
Actually, the question is: what happens from a physical point of view? Most likely ?

Answer 1

To the aforementioned wet shit wires, I can also add rats gnawing wires.
To confirm, I can take a picture of a piece of a 100-Mbit cable with gnawed copper wires at work on Monday, xs what kind of rats we have...