POST `/eth/v1/validator/{pubkey}/feerecipient` of an existing remotekey requires beacon-chain restart to register in the relay
**Describe the bug**

After successfully [POST feerecipient](https://ethereum.github.io/keymanager-APIs/#/Fee%20Recipient/setFeeRecipient) through **validator keymanager API**, it seems like the beacon-chain service (BN) does not register this new FeeRecipient to MEVBoost/relays. When querying the relay the [validator registration data](https://flashbots.github.io/relay-specs/#/Data/getValidatorRegistration), the old FR is still there

**Expected behaviour**

Nimbus beacon-chain registers the new fee recipient in the relay.

**To Reproduce**
Steps to reproduce the behavior:
1. Platform details (OS, architecture):  running nimbus as **multiservice**  with docker.
2. Branch/commit used: nimbus version 25.1.0
3. Commands being executed: POST fee recipient endpoint. See https://ethereum.github.io/keymanager-APIs/#/Fee%20Recipient
4. Relevant log lines: 

**Additional context**
Running nimbus in dappnode. See https://github.com/dappnode/DAppNodePackage-nimbus-generic