Best source for prices now?

When I select a security in Statement of Assets, I am not seeing prices/chart at the bottom (message “No prices available”) for some securities. The historic prices do show up in the dialogue box when I select the quote provider (e.g. “Yahoo Finance (adjusted close” or “Yahoo Finance”).

For example BP.L shows “No prices available”, SHEL.L works OK.
HSBC FTSE All-World Index C Acc (symbol: 0P00013P6I.L) works OK, but it’s income version HSBC FTSE All-World Index C Inc (symbol:0P00013P6J.L) does not.

Any ideas?

Also - I’m just learning with PP. What’s the appropriate way to report a repeatable bug?