Bitcoin Core – Listunspent not returning all utxos

I’m using Bitcoin Core to get all UTXOs for a Watchonly income address. The strategy is as follows:

1. Load a new wallet

   await client.execute("loadwallet", ("testwallet"))
   

2. Get multiple addresses in a loaded wallet

   import csv
   import time
   
   addresses = ()
   with open("addr.csv") as f:
       reader = csv.DictReader(f)
       for row in reader:
           timestamp = time.mktime(
               time.strptime(row("created_at"), "%d/%m/%Y %H:%M:%S")
           )
           addresses.append(
               
                   "scriptPubKey": "address": row("address"),
                   "timestamp": int(timestamp),
                   "watchonly": True,
               
           )
   res = await client.execute("importmulti", (addresses))
   print(res)
   

Then, when I calculate the utxos for one of the loaded addresses, I don’t get a list with all the utxos that I can find in the block explorer. Can you please give me some insight into what’s going on here and how to solve it without doing the heavy lifting like blockchain indexing?