Smartnode fails to claim when using a fallback client

smartnode version 1.6 amd64 primary ec/cc: geth/lighthouse fallback ec/cc: besu/teku

Expected behavior: After running rocketpool node claim I expected the smartnode to claim my rewards. Since I'm in the process of staking an archive node on my primary RP node, I am using a fallback client on the lan for ec activity. I'm aware of a different problem with the claiming process that is being investigated, but I don't believe this is related.

Actual behavior: After the claim is processed by the smartnode, the transaction was unsuccessfully submitted to the fallback ec (besu) for inclusion.

phiz@animal:~/.rocketpool/data/rewards-trees$ r n c -y

NOTE: primary clients are not ready, using fallback clients...
    Primary EC status: syncing (36.83%)
    Primary CC status: synced and ready

Welcome to the new rewards system!
You no longer need to claim rewards at each interval - you can simply let them accumulate and claim them whenever you want.
Here you can see which intervals you haven't claimed yet, and how many rewards you earned during each one.

Rewards for Interval 0 (2022-08-04 05:35:39 +0000 UTC to 2022-09-01 05:35:39 +0000 UTC):
    Staking:        ### RPL
    Oracle DAO:     ### RPL
    Smoothing Pool: ### ETH

Total Pending Rewards:
    ### RPL
    ### ETH

With this selection, you will claim ### RPL and ### ETH.

You currently have ### RPL staked (###% collateral).
If you restake ### RPL, you will have a total of ### RPL staked (the max collateral of 150%).
Restaking more than this will not result in higher rewards.

Automatic restaking is not requested.
Using a max fee of 9.98 gwei and a priority fee of 2.00 gwei.
Could not claim rewards: Post "http://192.168.6.28:8545": EOF

rocket-pool / smartnode

Smartnode fails to claim when using a fallback client #233