Issues with purchase clearing account

We are having an issue in our purchase clearing GL with returns.

In April we did a return to a vendor in USD for $67. The exchange rate was 1.2575 so it debited the purchase clearing GL by $84.26.

The credit note we received from the vendor was for $67 USD but had a March date with a different exchange so it was credited to the purchase clearing GL by $84.99.

For a difference of $0.73

The $0.73 does not show up in the purchase clearing under that vendor but I do have $0.73 in March as a debit but for a completely different company.

I can't see anything for the second company where we should have a $0.73 in the purchase clearing GL.

I assume they should all clear off but I don't understand why the exchange difference is showing as a different company in the GL.

Any suggestions