A 10X probe is more complicated than just plugging one in, if I read the schematic right. It is not your standard 1Mohm input, like all full size scopes. The 10X probes work as 10X because of an assumption of a standard 1 Mohm input to the scope. The DSO Nano has some other impedance, that varies with what V/cm scale you’re using at the time.
If you are just trying to watch a fairly low impedance signal, you could make a voltage divider that is far far lower impedance than the input impedance of the Nano, and be fine. If you had a 1k and a 9k resistor, the input z of the probe would be 10K and the actual input z of the Nano would be irrelevant. So, if 10k is acceptable, that works. Good luck. Irv