Seems like there's a good chance that you just have a low voltage problem at that receptacle. It might be that the panel or breaker is bad, but this is much less likely given your prior years using it.
You should check the amp rating on the breaker, and then find the amp requirements for your new dehumidifier. Since the previous units worked for some time and then died, it's probable that they required less power.
Dehumidifiers are commonly designed quite similar to a refrigerator or air conditioner, in that they usually have an electric motor. Electric motors generally don't like lower voltage than the listed requirement, and if the circuit they are on can't provide full voltage (under load) then they will tend to draw a higher current (amps) to compensate for the lower voltage. This higher current would put more demand circuit breaker.
Such a condition is hard on the electric motor, and if it persists, will accelerate the decline of the device. That may be what happened to your previous units. The older unit(s) might have had lower amperage requirements, but if the circuit isn't providing full voltage they'd still have drawn more amps.
If this newer unit has a higher base ampere requirement, and if it's not getting enough voltage, as it draws more amps to compensate, it may be drawing above the breaker's rating, where the older units might not have.
In order to resolve this, I think you need to do some research/trouble shooting on the whole circuit. It might be just one part of the circuit that is not suitable for the load, or it might be a combination of several smaller factors all adding up to a problem.
That fact that using the unit upstairs doesn't blow circuits, supports my premise.
It wouldn't be uncommon for an "add on" panel to be wired in with less potential than the main panel. I'd be checking the entire circuit, including the main wires going IN to the basement panel, the connections made with the wiring, the connection of the breaker itself into the panel, the wires going on out to your receptacle, connections going into your receptacle (might be corrosion or bad connection) and generally the receptacle itself. The whole system.
You need to know (and can find on the dehumidifier, what amps and voltage it requires for your start. If all the connections are clean and good from the inbound wires TO the panel, and each step into the receptacle, then you have to consider if the wiring itself (into and from the panel) is sufficient for the load you're asking it to carry.
This means considering the wire diameter, the wire material, and the distance from the power source, through the panel and breaker and on to the receptacle.
If all or any of those wires aren't suited to carry the load you need, you'll likely have low voltage, higher amp draw and breaker unhappiness, or worse...
Even if you have just one bad connection anywhere along this circuit, the same result. It could even be a badly "kinked" or severely bent wire causing the issue, so during inspection, you have to really look it all over and see what's there.
Where do the wires come from, that are going into that panel? From the street direct or from you other panel? If the latter, there's possibly another breaker there which again has to be considered in the load/ampere and voltage loss calculation.
You can easily find online a wire-size voltage loss calculator, you input the wire material (copper or aluminum), diameter and length of the run and it will tell you the voltage loss you'd likely experiencing.
You might start just testing the voltage to the receptacle, without any load, and if it's a double receptacle, you can then turn on the dehumidifier and test the voltage again and you'll see if and how much voltage you have under load, and if it's enough.
Maybe you have an A/C amp/load tester in which case you can learn that number to.
Or, you might return the new dehumidifier, after learning what it's voltage/amperage requirements are, and buy one with significantly less requirements and do none of the above. But, determining the cause, fixing the problem, will likely save you money over the long haul.
Be safe. Turn off the power for investigating the wires/connections. Get qualified help if you aren't sure. I'm not a professional so my suggestions aren't worth the money you didn't pay for them!
