Aeotec Nano Switch ZW116 stopped working

Just over a month ago, I got an Aeotec Nano Switch ZW116 with energy monitoring and wired it up to my dishwasher in order to get usage notifications via a webCoRE piston. I used a custom DTH by @madj42 (and read that he uses the ZW116 for this same purpose).

It all worked swimmingly for over a month, but then things started getting wonky and I noticed a few days ago that I was no longer getting Power (W) updates in the device event history, just Voltage (V) ones, despite settings to the contrary. I also noticed that the device had networkSecurityLevel: ZWAVE_LEGACY_NON_SECURE despite having paired it in secure mode (or so I thought). Thus, I decided to exclude it from my (V3) hub and start over.

I reset and re-paired the device (successfully as ZWAVE_S0_LEGACY this time, after temporarily moving my hub closer to the dishwasher). Then, as I was getting ready to run the dishwasher and test the setup, the switch abruptly shut itself off, and could not be turned on via the switch’s “Action Button” nor the SmartThings app. I turned off the circuit breaker and checked that the wires were securely connected, then turned the circuit breaker back on. The switch turned on, but then shut itself off again after a minute or so. I tried this several times and the switch always turned on for a short period of time before shutting itself off (and being completely unresponsive).

Has anyone else encountered this before? Any ideas for troubleshooting?

(@TheSmartestHouse FYI, I emailed your customer support about this too since I bought the switch from you. I’m hoping that, with the help of the community, I’ll be able to get this resolved without having to send it back!)