Yep, the Intel C2000 CPU LPC Clock degradation issue, as mentioned by @LutherP.
The clock will continue to degrade, so it’s unknown how long the pull-up resistor will remain effective.
Likewise, I did the 100 ohm resistor patch to my TS-251. However, after recovering my data, I decided to move on to a new NAS, so I wouldn’t have to worry about a reoccurence.