For live prices, what counts is the Price listing (the exchange code). Your own ticker, the ISIN and the WKN are separate from it.
Ticker: your label in trades, holdings and activity (for example SAP or BTC). Use whatever you know from your statement.
Price listing: the exchange code for live prices (for example XETR:SAP or SAP.DE).
ISIN: an optional 12-character international identifier (for example DE0007164600). Helps with matching imports.
WKN: an optional 6-character German securities identifier (for example 716460).
Listing market (US-listed or Europe-listed) isn't an identifier. It depends on where the price listing trades, not where the company is based, and controls the split on the Overview.
Keep ticker and price listing separate when they differ. Renaming a ticker doesn't change the price listing, ISIN or WKN. Bitcoin uses the ticker BTC.