"If you ever make a payment, they are moved away! You have to move them back!" You mean a btc payment or a byteball payment?
Well both

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"You cant just link once and then go pay other things - the wallet moves your bytes away." Can you please explain ... Thanks!
The idea is that if you link and use the balances from your linked addresses to do transactions, then your balance with constantly change from one address to the other, meaning you either have to link new addresses or send your funds back to your initially linked addresses and stop doing (outgoing) transactions.