Forger plugin doesn't collect any data running on the testnet

[przemerr]

Expected behavior

Forger plugin should work and collect data

Actual behavior

Forger plugin loads and responds to calls but doesn't collect any data. Additionally there's an error thrown in the lisk-core logs:

(node:1242) UnhandledPromiseRejectionWarning: Error: Specified key blocks:height:00d6c57b does not exist
    at parseError (/home/lisk/.nvm/versions/node/v12.22.1/lib/node_modules/lisk-core/node_modules/lisk-framework/dist-node/controller/bus.js:20:12)
    at Bus.invoke (/home/lisk/.nvm/versions/node/v12.22.1/lib/node_modules/lisk-core/node_modules/lisk-framework/dist-node/controller/bus.js:125:23)
(node:1242) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)

Steps to reproduce

Run the lisk-core with the forger plugin loaded on the testnet, check if data is collected.

Which version(s) does this affect? (Environment, OS, etc...)

lisk-core 3.0.0-rc.2