Reminds me of a random google SRE slide deck I stumbled across a couple of years ago. Switch itself corrupts payload; dense enough to pass the tcp checksum in use.
This. I work at a CDN and there's a particular switch model that we have a fair number of doing this. It was incredibly hard for the network team and vendor to track down. It's because one of the internal data paths was not error checked (i.e. hw design and layout problem). We're somewhat working around it with application layer stuff, but are moving off that switch and vendor as fast as capex allows. It wasn't a bottom of the barrel vendor either.