My balance sheet shows different accounts numbers then the numbers at the banking dashboard. The bank accounts where already positively reconciled. Do you know solution?

I recently reconciled all of my accounts but for two of them (USD & PLN) I had to use contra account in GBP due to the moeny movement between multlicurencies. As the GBP rate vs usd and pln was different then the one I had in bank at the time of the transactions I was typing in my own rate copied from bank at the time. The accounts were reconclied positively, everything was correct. But now when I run balance sheet report I see different ending banalce then the one that was reconciled. For example I have USD 00.00 on 31/07/21 in banking dashboard and reconciliation report but in balance sheet it shows -13.92 on 31/07/21. I saw that in balance sheet the gbp rates are different then the ones I had in bank transfers which were reconciled. Can you help with solving this?