RE: LSE v ASX v US OTC12 Mar 2021 14:57
13:35 88E is listed on ASX (Chi-X) & AIM, share is same ISIN code.
Think that rather comparing tickers you check what share are actually trading at, there will be differences between SH & NH due to time differences, market rules and operations and of course currencies, there I believe is an agreed scheme of arbitration between ASX & AIM although I have never seen it employed
As for OTC (Over the Counter) that is not an "exchange" as ASX or AIM and not an official listing but your choice if you think it offers a better deal / liquidity.