Cachow, sorry to hear that you're having that issue. I've purchased a number of items from them directly with no issues. I did purchase a Z-Stuff signal bridge from Ross Custom Switches which I sent back to Z-Stuff to be fixed....and it was fixed with quick turnaround. Dennis Zander was great to deal with....
I've never had any issues with wires that needed to be resoldered.
I'm not an electronics guy, but their wiring diagrams and instructions make it easy to hook their accessories up, and I've found that they do work fine.
They've made it real simple for me, so I've never had to look at another supplier of these types of products. Maybe they obtain some components for their pieces from China, so it's entirely possible that their supply chain has been impacted/delayed by the virus.
Hang in there and good luck!
