I normally see parity errors on the console during system boot diagnostics along with the SCHAN errors and have always assumed hardware issues with the memory subsystem and RMAs have always been handled without question.
You are correct that unplugging and plugging ports can force the generation of error messages. When traffic does flow, performance is very poor. SCHAN errors can be seen on a test bench with minimal traffic, e.g. a single laptop connected to the switch with no other traffic. The SCHAN errors will normally appear immediately.
I would imagine that I would have tried clearing the configuration and concluded that that did not help, but I will certainly try that again when I next see a switch with SCHAN errors.
