import qif files adds other accounts that have transfers between them

I'm migrating from an old version of Quicken and would like to be able to use Homebank but I'm having trouble importing my QIF files. I have 5 accounts all exported from Quicken as individual QIF files, which I'll refer to as file 1,2,3,.. etc.

I haven't set up any accounts in Homebank, just changed some of the preferences. I started by importing File 1 which went ahead as I expected. I chose to import it as a 'New Account' in the options and named it the same as it was in Quicken (for simplicity). It imported everything as expected BUT it also added 3 of my other accounts, with partial transactions only. So I imported one of these accounts, say File 2, thinking it would include the transactions that were missing.

It didn't? Instead it added further transactions to File 1, duplicated many transactions in File 2 and added the fourth account with a few transactions. I discovered the transactions which caused it to install the other accounts were transfers between any two accounts, which I can sort of understand - if it's a transfer between accounts it needs to have both sides of the transaction so at the first import it has to create them. I thought maybe if I imported them all the duplications might cancel themselves out but not so.

Now I have no idea what the correct balance should be in each account or how to correct it. I've even uninstalled HomeBank but it obviously stores data somewhere because when I re-installed it the same balances came up.

The only way I can see of avoiding this is to manually delete any transaction I don't want to include in the import but this is totally impractical with more than 10 years worth of transactions in the main account (File 1). It would take days even if I could identify which ones I don't want (which I can't) so there must be a more straightforward way of importing one account without other accounts being automatically set up. I've tried a few products none of which have behaved in this manner - I've just clicked import and it imports data for that file only, which is how I expected HomeBank to work.

The question therefore is how do I import data from one QIF file at a time without HomeBank setting up another account with internal transfers in it? Meanwhile, how do I clear HomeBank of all data so I can start again with a fresh copy. Any help will be much appreciated.

I'm using HomeBank v5.1.1. on the latest version of Windows 10 (20H2).