How recent is the transaction? What is the time range set to (top-right corner of Kibana)? It may be that the UI is not setting the time range appropriately for older transactions. It should just work, but it's possible that the time range isn't being properly set by the APM UI.
You're right, the time range doesn't get carried through to Discover, nor does the index. Setting the index to apm* (Kibana has two index patterns of apm* after loading them through the GUI) and a matching time range does show the transaction.
If you import the index patterns via the APM getting started instructions screen, you should receive a warning about overwriting objects. Do you get that? Also, if you don't mind overwriting your APM dashboards and visualisations, please proceed and overwrite them.
I expect this will fix the error with missing index patterns.
Let me know if it doesn't.
I've now deleted and reloaded the Kibana APM objects. I still get the message on the APM screen that there's no APM index pattern however I do only have one index pattern listed. The result of that query is now:
Now I'm interested in knowing whether Kibana is correctly picking up your changes to kibana.yml. There is no direct way to figure this out, so it'll be slightly messy. I hope you'll indulge me
After opening the APM tab in Kibana, please click "View source" in your browser and search for "apmIndexPattern" - it should be hiding inside a blob of urlencoded data. I'm interested in the first 60ish characters after apmIndexPattern like:
From the encoded blob, I can see that your config change works, and apm* is the index pattern title we are looking for. I can also see that you index pattern is correctly created with a title of apm*. Therefore it should work as expected.
Since you are still seeing an error message, there must be an error elsewhere, and I'll have to spent some more time looking into this before I can give you a good answer. I don't have a timeline right now for when that'll be.