Ok, I found the problem.

There is currently a bug with account history on Hive Engine that is reporting null for certain records.

For example:

{'_id': '614dd89d8bae125202f7a86a', 'blockNumber': 10720751, 'transactionId': '2538233dac47482c98e1b648dd71c0c97f9e7ea3', 'timestamp': 1632491670, 'operation': 'market_sell', 'symbol': 'STARBITS', 'to': None, 'quantityTokens': None, 'quantityHive': '15000', 'account': 'lallo'}

You can see here that you sold to no one, which isn't possible.

I wrote some code to detect this and ignore it, this may slightly alter the accuracy of the tool in this case as I have no way to know the actual quantity when this happens.

I have reported it to one of the developers and they are looking into it.

The tool works now, but I am not sure what these records are and if they are missing information (would effect results), or just fake transactions (won't effect results).