Cannot read property 'getGlobalStorage' of undefined

[StErMi]

I'm reporting the issue also here so people that will come across will find an open ticket.

I've setup the example, run npm run dev and the second (and all the next) time I call the API I get this error:

offline: GET /book (λ: book)
offline: (λ: book) RequestId: ckev43u0x0002z8l3clxrh6eo  Duration: 464.85 ms  Billed Duration: 500 ms
offline: GET /book (λ: book)
offline: Failure: Cannot read property 'getGlobalStorage' of undefined
TypeError: Cannot read property 'getGlobalStorage' of undefined
    at Object.<anonymous> (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/node_modules/@mikro-orm/core/metadata/MetadataStorage.js:63:42)
    at Module._compile (internal/modules/cjs/loader.js:1138:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
    at Module.load (internal/modules/cjs/loader.js:986:32)
    at Function.Module._load (internal/modules/cjs/loader.js:879:14)
    at Module.require (internal/modules/cjs/loader.js:1026:19)
    at require (internal/modules/cjs/helpers.js:72:18)
    at Object.<anonymous> (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/node_modules/@mikro-orm/core/metadata/index.js:15:14)
    at Module._compile (internal/modules/cjs/loader.js:1138:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
    at Module.load (internal/modules/cjs/loader.js:986:32)
    at Function.Module._load (internal/modules/cjs/loader.js:879:14)
    at Module.require (internal/modules/cjs/loader.js:1026:19)
    at require (internal/modules/cjs/helpers.js:72:18)
    at Object.<anonymous> (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/node_modules/@mikro-orm/core/utils/Configuration.js:10:20)
    at Module._compile (internal/modules/cjs/loader.js:1138:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
    at Module.load (internal/modules/cjs/loader.js:986:32)
    at Function.Module._load (internal/modules/cjs/loader.js:879:14)
    at Module.require (internal/modules/cjs/loader.js:1026:19)
    at require (internal/modules/cjs/helpers.js:72:18)
    at Object.<anonymous> (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/node_modules/@mikro-orm/core/utils/index.js:13:14)
    at Module._compile (internal/modules/cjs/loader.js:1138:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
    at Module.load (internal/modules/cjs/loader.js:986:32)
    at Function.Module._load (internal/modules/cjs/loader.js:879:14)
    at Module.require (internal/modules/cjs/loader.js:1026:19)
    at require (internal/modules/cjs/helpers.js:72:18)
    at Object.<anonymous> (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/node_modules/@mikro-orm/core/entity/EntityFactory.js:4:17)
    at Module._compile (internal/modules/cjs/loader.js:1138:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
    at Module.load (internal/modules/cjs/loader.js:986:32)
    at Function.Module._load (internal/modules/cjs/loader.js:879:14)
    at Module.require (internal/modules/cjs/loader.js:1026:19)
    at require (internal/modules/cjs/helpers.js:72:18)
    at Object.<anonymous> (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/node_modules/@mikro-orm/core/entity/EntityAssigner.js:5:25)
    at Module._compile (internal/modules/cjs/loader.js:1138:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
    at Module.load (internal/modules/cjs/loader.js:986:32)
    at Function.Module._load (internal/modules/cjs/loader.js:879:14)
    at Module.require (internal/modules/cjs/loader.js:1026:19)
    at require (internal/modules/cjs/helpers.js:72:18)
    at Object.<anonymous> (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/node_modules/@mikro-orm/core/entity/index.js:17:14)
    at Module._compile (internal/modules/cjs/loader.js:1138:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
    at Module.load (internal/modules/cjs/loader.js:986:32)
    at Function.Module._load (internal/modules/cjs/loader.js:879:14)
    at Module.require (internal/modules/cjs/loader.js:1026:19)
    at require (internal/modules/cjs/helpers.js:72:18)
    at Object.<anonymous> (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/node_modules/@mikro-orm/core/index.js:21:14)
    at Module._compile (internal/modules/cjs/loader.js:1138:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
    at Module.load (internal/modules/cjs/loader.js:986:32)
    at Function.Module._load (internal/modules/cjs/loader.js:879:14)
    at Module.require (internal/modules/cjs/loader.js:1026:19)
    at require (internal/modules/cjs/helpers.js:72:18)
    at Object.@mikro-orm/core (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/.webpack/service/src/handlers/book.js:2869:18)
    at __webpack_require__ (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/.webpack/service/src/handlers/book.js:20:30)
    at Object.../../../src/handlers/book.ts (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/.webpack/service/src/handlers/book.js:463:16)
    at __webpack_require__ (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/.webpack/service/src/handlers/book.js:20:30)
    at /Users/stermi/dev/workspace/serverless-mikro-orm-example-app/.webpack/service/src/handlers/book.js:84:18
    at Object.<anonymous> (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/.webpack/service/src/handlers/book.js:87:10)
    at Module._compile (internal/modules/cjs/loader.js:1138:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
    at Module.load (internal/modules/cjs/loader.js:986:32)
    at Function.Module._load (internal/modules/cjs/loader.js:879:14)
    at Module.require (internal/modules/cjs/loader.js:1026:19)
    at require (internal/modules/cjs/helpers.js:72:18)
    at /Users/stermi/dev/workspace/serverless-mikro-orm-example-app/node_modules/serverless-offline/dist/lambda/handler-runner/in-process-runner/InProcessRunner.js:80:133
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
    at InProcessRunner.run (/Users/stermi/dev/workspace/serverless-mikro-orm-example-app/node_modules/serverless-offline/dist/lambda/handler-runner/in-process-runner/InProcessRunner.js:80:9)

Note: The only different thing from the example is that I'm using @mikro-orm/postgresql@4.0.0-rc.1 instead of the mysql package.

what could be the issue?