Mongo-URL Key without effect

[cc4in]

Hey there,

I want to run multiple instances of WeKan via Snap, but use only one DB-Server.
I'm able to install this via snap, but the option for the mongo-url does not seem to work and i can't find why:

root@server:/snap/wekan_test/1304/bin# snap get wekan_test
Key        Value
mongo-url  mongodb://127.0.0.1/wekan2
port       8081
root-url   https://<url-censored>

I'v got a MongoDB running on 127.0.0.1 with the DBs /wekan and /wekan2.

Tried with Version 4.91 Rev 1304 and 4.91 Rev 1311.

Log Entrys show something like this:

2021-02-01T13:44:19Z wekan_test.wekan[2470642]: MONGO_URL=mongodb://127.0.0.1:27019/wekan
2021-02-01T13:44:21Z wekan_test.wekan[2471485]: /snap/wekan/1311/programs/server/node_modules/fibers/future.js:313
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:                                                 throw(ex);
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:                                                 ^
2021-02-01T13:44:21Z wekan_test.wekan[2471485]: MongoNetworkError: failed to connect to server [127.0.0.1:27019] on first connect [Error: connect ECONNREFUSED 127.0.0.1:27019
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:     at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1144:16) {
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:   name: 'MongoNetworkError'
2021-02-01T13:44:21Z wekan_test.wekan[2471485]: }]
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:     at Pool.<anonymous> (/snap/wekan/1311/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb/lib/core/topologies/server.js:438:11)
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:     at Pool.emit (events.js:314:20)
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:     at /snap/wekan/1311/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb/lib/core/connection/pool.js:562:14
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:     at /snap/wekan/1311/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb/lib/core/connection/pool.js:995:11
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:     at /snap/wekan/1311/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb/lib/core/connection/connect.js:32:7
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:     at callback (/snap/wekan/1311/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb/lib/core/connection/connect.js:280:5)
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:     at Socket.<anonymous> (/snap/wekan/1311/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb/lib/core/connection/connect.js:310:7)
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:     at Object.onceWrapper (events.js:421:26)
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:     at Socket.emit (events.js:314:20)
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:     at emitErrorNT (internal/streams/destroy.js:92:8)
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:     at emitErrorAndCloseNT (internal/streams/destroy.js:60:3)
2021-02-01T13:44:21Z wekan_test.wekan[2471485]:     at processTicksAndRejections (internal/process/task_queues.js:84:21)
2021-02-01T13:44:21Z systemd[1]: snap.wekan_test.wekan.service: Main process exited, code=exited, status=1/FAILURE
2021-02-01T13:44:21Z systemd[1]: snap.wekan_test.wekan.service: Failed with result 'exit-code'.
2021-02-01T13:44:21Z systemd[1]: snap.wekan_test.wekan.service: Scheduled restart job, restart counter is at 408.
2021-02-01T13:44:21Z systemd[1]: Stopped Service for snap application wekan_test.wekan.
2021-02-01T13:44:21Z systemd[1]: Started Service for snap application wekan_test.wekan.
2021-02-01T13:44:22Z wekan_test.wekan[2471498]: DEBUG=false (default value)
2021-02-01T13:44:22Z wekan_test.wekan[2471498]: MONGO_LOG_DESTINATION=devnull (default value)
2021-02-01T13:44:22Z wekan_test.wekan[2471498]: MONGO_URL=mongodb://127.0.0.1/wekan2
2021-02-01T13:44:22Z wekan_test.wekan[2471498]: MONGODB_BIND_UNIX_SOCKET= (default value)
2021-02-01T13:44:22Z wekan_test.wekan[2471498]: MONGO_URL=mongodb://127.0.0.1/wekan2
2021-02-01T13:44:22Z wekan_test.wekan[2471498]: MONGODB_BIND_IP=127.0.0.1 (default value)
2021-02-01T13:44:22Z wekan_test.wekan[2471498]: MONGODB_PORT=27019 (default value)
2021-02-01T13:44:22Z wekan_test.wekan[2471498]: MAIL_URL=smtp://user:[email protected]:25/ (default value)
2021-02-01T13:44:22Z wekan_test.wekan[2471498]: [email protected] (default value)

And systemctl journal:
Feb 01 14:45:01 .SERVER wekan_test.wekan[2483396]: SAML_ISSUER= (default value) Feb 01 14:45:01 .SERVER wekan_test.wekan[2483396]: SAML_CERT= (default value) Feb 01 14:45:01 .SERVER wekan_test.wekan[2483396]: SAML_IDPSLO_REDIRECTURL= (default value) Feb 01 14:45:01 .SERVER wekan_test.wekan[2483396]: SAML_PRIVATE_KEYFILE= (default value) Feb 01 14:45:01 .SERVER wekan_test.wekan[2483396]: SAML_PUBLIC_CERTFILE= (default value) Feb 01 14:45:01 .SERVER wekan_test.wekan[2483396]: SAML_IDENTIFIER_FORMAT= (default value) Feb 01 14:45:01 .SERVER wekan_test.wekan[2483396]: SAML_LOCAL_PROFILE_MATCH_ATTRIBUTE= (default value) Feb 01 14:45:01 .SERVER wekan_test.wekan[2483396]: SAML_ATTRIBUTES= (default value) Feb 01 14:45:01 .SERVER wekan_test.wekan[2483396]: ORACLE_OIM_ENABLED=false (default value) Feb 01 14:45:01 .SERVER wekan_test.wekan[2483396]: MONGO_URL=mongodb://127.0.0.1:27019/wekan

I dont understand this - I assume at first the instance uses the default value 127.0.0.1/wekan, but snap the rewrites that to 127.0.0.1/wekan2 - but it does not have any effect.
By the way - the default connect to 127.0.0.1/wekan is in effect, because both my test-boards run and have the same users - therefore seem to share this one DB.

Am I doing something wrong? Or is it maybe a bug?

Regards

Manuel