So I'll try and lay out the scenario as simply as possible as something appears to have changed with QBO recently:

Base currency is GBP

Sales invoice in question below is in EUR

Bank account is a EUR bank account

- bank feed shows a deposit in bank account that can be matched to an outstanding sales invoice (for eg. €1200)

- click match to match €1200 bank deposit to outstanding €1200 sales invoice dated 20.10.20

- view the customer's account/transaction list, and the €1200 receipt is being shown with a 1:1 exchange rate between € & £ when viewing the 'receive payment screen', thus in effect saying that the €1200 receipt is equivalent to a £1200 receipt and creating a realised exchange gain/loss as a result.

- if you click on the date field, alter it to another date and then set it back to the correct date  it then updates the exchange rate to the actual rate (0.912759)

This is obviously a large amount of additional work and makes the matching from the bank screen useless if we then have to go into each transaction and mess about to get the correct exchange rate to be applied.

What is causing this initial/default setting of a 1:1 rate when matching deposits from the banking screen? 

Thanks in advance for any insight.