The Asset Group Summary report in AA shows the Opening Cost (Acquisition Cost plus any Additional Costs) and Opening WDV (written down value).
Your balance sheet accounts will show the cost at acquisition for the asset group, total accumulated depreciation, and then further, the WDV which is the combination of those two.
Why may there be a difference matching the Asset Group Summary report numbers with the balance sheet?
Usually this apparent mis-match and confusion is caused when you have previously made asset transfers from one asset group to another.
Asset group transfers are tracked and audited in AA, however when transferring from group to group, AA takes the date of the transfer into account.
Therefore not all P&L and balance sheet items will be moved between groups, depending on the transfer date you choose.
If you're transferring assets in and out of groups from the First Use date, things should always balance.
But if you're transferring between asset groups sometime after first use, some depreciation transactions will remain in the original asset group prior to the transfer date, which is the correct treatment.