getbalance and listaddressgroupings inconsistent
You are using getbalance incorrectly. You have specified an account name of the address that you want the balance for. However this is not how getbalance works. Bitcoin does not use accounts and addresses are not accounts. An account here means an account in Bitcoin Core's internal accounts system which has since been removed.

So your command getbalance mmUToPM2vBb2F1ZNcR86J12GxqAbUJtFCr is asking for the balance of the account named mmUToPM2vBb2F1ZNcR86J12GxqAbUJtFCr, but no such account exists. The account that has the address mmUToPM2vBb2F1ZNcR86J12GxqAbUJtFCr is named From Electrum Wallet. Thus the command you should be using is

getbalance "From Electrum Wallet"