When creating invoices, one of the time entries shows a different value for Hours (say 7.5 hours) than the Hours in the Time Entries screen (say 8 hours). How to fix that?
The hours you see on an invoice are Client Hours, which are normally hidden in the Time Entries list view and automatically take the same value as the Hours field. However, you can change it to a different value. Check the Core Help for details. In your case, the Hours and Client Hours for the time entry are different and so Core has brought forward the Client Hours on the invoice. To fix this, you need to delete the invoice, correct the Client Hours on the time entry and then recreate the invoice.
Note: The hours on an invoice are also adjusted if there is a Write-Up/Down (WUD) on the time entries. Check the Core Help for details.