Hello,
Based on the articles I have read about same ETFs in different currencies, the currency in which ETF is traded should not have an impact on return. However when I bought the same ETF in demo account in 3 different currencies the return is different. I bought “iShares MSCI USA ESG Screened” in USD, EUR and GBP. My Trading212 currency is Czech crown.
I think this is because you have held the shares for only a very short time. Wait to look at the changes over a longer time. The bid for SASU may not always perfectly align with the bid for GPSA. There may be differing investor demands for these versions of the same underlying fund.
There will be small differences in returns, but not so great that you could consistently make better money choosing one rather than the other, or by swapping between them.