Hello Lima Saudara,
Stock move done with 28 qty it doesn't mean you have 28 qty in stock at that time. It means product moves has been created with 28 qty to make your theoratical and counted qty equal.
Actually on the product view (listview / formview) shows the quantity including all your warehouses and the forecasted quantity considered confirmed sales which are not done yet (means outgoing quantity), so if you have any open sales then it will be reflected to the forecasted quantity.
One more factor is, if you have multiple warehouses then it will shows the forecasted quantity combined of all your warehouses.
To check the proper stock go to INVENTORY => REPORTING => INVENTORY REPORT
Remove Group by option Product > Location and set new group by Location only.
Here you will get the detailed stock for all the locations. You can also hide/ see the reserved quantity field.