It is the model that is listed on the Meraki datasheet you link to.  They are sold as Cisco SFPs now that is what it says on the box they came in.  It is the MA-SFP-1GB-SX, and they are not cheap, but now I have some, as well as others we use, so if I have an issue, I can put a supported model on each end of the connection.  The firmware upgrade fixed the issue.  Thank you to all for your help. ... View more

I can't tell you how many times I didn't realize how big a change was going to be beforehand.  It always seems to find a way to affect more than what you first realize.  Good you got things figured out, and are getting some help with getting it right.  You must have a pretty huge network, and a complicated one at that.  Good luck!     ... View more