Help debugging server error, when using replicaset, was working

I had some issues with a mongo cluster, I had to reboot all instances and I can connect to the replicaset again with a CLI mongo client… but not in my Meteor app. I can connect my Meteor app to a single mongo node (the primary), but when I try the replicaset/cluster URL it dies and restarts, over-and-over.

Thinking I was somehow messing up my app, I just cloned the todos example app, put in the connection URLs to my production database cluster, and deployed it (via mup if you think that matters). It too, can not connect, and has the same issues.

I’m looking for advice on how to troubleshoot this.

Here is the console log of the deployed instance

=> Starting meteor app on port:80

[object Object]

When I turn on profiling and debugging I got the fibers error in a weird place, but perhaps that’s a red-herring.

|    ├─ packages/ddp-server.js.....................................53 ms (1)                                                       |    │  ├─ require("./node_modules/meteor/ddp-server/livedata_server.js") 3 ms (1)
|    │  └─ require("./node_modules/meteor/ddp-server/server_convenience.js").49 ms (1)                                             |    │     ├─ Npm.require("sockjs")                                40 ms (1)
|    │     ├─ Npm.require("permessage-deflate")                     3 ms (1)

|    │     └─ other require("./node_modules/meteor/ddp-server/server_convenience.js") 6 ms

sidenote - if mdg felt like it, I’ve run into a few fibers-wrapped-impossible-to-determine-issues in the past, and whatever the hell this [object Object] is could use some better debugging… i’m just sayin`