I guess that it’s because the bot doesn’t save the amount you traded and isolates it.
I mean, if you have the pair USDT-BTC and you buy 1000$ worth BTC, it should save anywhere USDT-BTC pair bought X BTC for 1000$ . For example if you deposit 0.02 BTC, it would sell it to USDT and count it as profit.
May look easier than it really it is, as the bot should detect when a crypto has been deposited as bot add it to secondary pair as it’s not trading profit. I will ask dev team about this and I will let you know if they plan to improve this somehow.