Cleo pulls your transactions on average twice daily. If it is just your most recent transactions that aren't showing it could be that they just haven't updated recently.
To make sure you have the most up to date transactions just say "refresh" to Cleo in messenger and Cleo will let you know when your accounts have been updated.
If you're on your dashboard, click on the refresh button next each account.
Available balance Vs Actual balance
Cleo shows you two balances
Available - This is the amount of money you have in your bank account that is available to spend with any pending transactions already deducted and not including any arranged overdraft.
Actual - This will be the amount you have in your account with any overdrafts taken into account and pending transactions will not always have been deducted. This number could be in the minus if you are in your overdraft for example.
Both of these numbers are taken from pulling your accounts twice daily alongside your transactions so if they are not accurate please try the refresh option above.