When using Airtable’s sort feature, you should see a switch in the sort setup that says, “Keep sorted”. This will ensure that the records stay sorted, even as you add new ones to the table.
Also, if you’re not already using multiple views, that may also help. Perhaps have one view that shows all the records sorted by date, and another one where you can apply filters to search for specific things. Only use the second view for filtering, and leave the main view with everything sorted by date.
Do either of these ideas help?