v2.0.0 connectivity issues

[nicoskk]

I recently updated the package to v.2.0.0 from v1.1.0 and i cannot connect to the mongoDB. The error i get is:
{"error": "server selection error: context deadline exceeded, current topology: { Type: ReplicaSetNoPrimary, Servers: [{ Addr: 127.0.0.1:27017, Type: Unknown, Last error: connection() error occured during connection handshake: dial tcp 127.0.0.1:27017: connect: connection refused }, ] }"}

Database used is mongo 4.4, and i've also tried 4.2 but i had the same error.
My environment variables are:
environment:
- "OTR_MONGO_URL=mongodb://mongo/local?replicaSet=repl1"
- "OTR_REDIS_URL=redis://redis"
- OTR_LOG_DEBUG=1

Both mongo and oplogtoredis are running inside containers, on the same network

Any help please?