Yoroi Wallet - ADA disappears from Public Address after staking?

Transfered some funds to Yoroi (held in Ledger Nano).
I created x4 Wallet addresses within the Yoroi wallet, each with varying amounts of ADA.

When I staked all my ADA, the first Wallet Address which had ADA in it, no longer shows the amount of ADA - so wondering why this is the case.

Note - the other 3 Wallet address still show the amount of corresponding ADA, and the ‘total ADA amount’ at the top of the page is still correct.

Anyone know what has happened here?

Cheers,

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