I hope you ordered low ESR type except big cap. General purpose 105oC capacitors won't last. Now rethinking about those waveforms, did you capture those while PSU was disconnected from the rest of the circuit? It may fail to work properly without any load attached. SMPS needs a minimum load and there does not seem to be any dummy load resistor present on the PCB.
I would suggest to measure while it is connected to the rest of the circuit or attaching some dummy load to at least one of the rails. Something that would sink at least 0.5W, say <47R on 5V rail or <200R on 12V rail.